Student budget eating guide

Okay, so strictly speaking this isn't actually a science post, but my sister is about to go to university and wanted some advice on eating cheaply for her friends and her. I really struggled for money when I was a student and have written up some of the tricks I used for saving money on my food bills. I thought that you might find this advice useful too, so I thought I'd post it here. 

Also, the point of this post is to help and advise people so please spread it to anyone you know who might find it useful - I know that plenty of people wouldn't look twice at a science blog, but could still benefit from this post!

Anyway, here it is!

The best way I found to budget for food was to plan all of my meals in advance. I used to do one big shop a week and made sure that I bought 21 meals of food in this trip (which is 7 breakfasts, 7 dinners and 7 teas). By doing this, I found I was able to set an affordable budget that I was able to stick to – the last thing you want to do is buy meals one or two at a time by shopping in supermarkets a few times a week. This makes it much harder to keep track of what you are actually spending because your bills are split into many different sessions and you end up spending way more. It’s also dangerous because the overall bill of each day is smaller than it is in one big shop, which used to trick me into thinking that I was spending less than I actually was.

A good trick that used to help me do this was to actually withdraw my allotted food budget in cash at the start of the week (I always made sure not to draw more out later). Mine was £15 a week, but I could have probably got this to less than £10 if I was really disciplined in what I bought (which is what most of budgeting actually comes down to). Anyway, I used withdraw £15 and then go and do my big shop. (When I was first getting into the habit of budgeting, I used to leave my card at home after withdrawing my cash out so I would have to put something back if I was over £15 – I literally couldn't pay for it)! If the overall bill was under £15, I used to put it in a pot for emergencies, snacks or let it slowly build up to £15 (so I wouldn't have to take money out on a week where I was really desperate).

Once you've done your big shop, try and stay out of supermarkets as much as you can. Only go in for things little things like milk and drinks.

Another piece of good advice is to ignore the special offers on things you don’t really need. These offers work by sucking you in on impulse buys and are always a sure way to blow your budget. You just end up with all these cakes (for example) that you don’t really want/need and most of them probably go off anyway because you can’t eat them fast enough. Secondly, if you actually spend the time to work out the maths in-store, they don’t even save you that much money. I found that the best way to avoid these deals was to make a list before you go shopping and the head straight to where the items are in the isles (and then straight to the tills without looking around too much). Saying that though, special offers can be a great way of saving money so look out for them on things you need or buy a lot (they crop up on healthcare products like toothpaste and shower gel all the time). 

Probably the hardest thing to budget for is alcohol. I never really got the hang of it to be honest, but I recommend that you don’t try to include it in your food budget and give it its own special one. Buy it in bulk as well – buy crates for cans/bottles and the biggest volumes of spirits you can afford – this is more expensive at the time, but works out way cheaper in the long run. Take advantage of the special offers as well! This might not be as applicable for you as it was for me (as I lived in the main student area of Manchester), but supermarkets used to slash prices of alcohol after holidays and exam periods so stock up then. I got 66 cans of Fosters for £20 once! Bear that in mind as it’s well worth keeping your eyes peeled!

Finally, don’t be conned into thinking that food from the big brands taste nicer than the supermarket own-brand ones – there’s usually very little difference in taste and the own-brand ones are cheaper and come in bigger packets. Avoid cheap, processed meat as much as possible, but it’s fine to buy everything else from cheaper brands. There’s not really any need to buy the very cheap own-brands either in most circumstances (as long as you are budgeting properly). I used to get away with buying Sainsbury’s Superior brands most of the time rather than Basics. For things like pasta and rice though, it doesn't really matter as Basics is just the same as Superior but in different packaging – it’s a ploy that supermarkets use all the time so don’t fall foul of it!

Anyway, that’s the best general advice I can give you. Budgeting for food is easier than you think – you've just got to sit down, work out what you can afford to spend each week and stick to it. Work out all your monthly outgoing costs – rent, bills and transport fares – and then how much you have coming in each month. The difference is your food, alcohol, going out and general shopping budget. Remember you can’t control your rent and bills, but you still have to pay them so make sure that this is a priority. Believe me when I say that it’s not fun being threatened with legal action and bailiffs by your landlord/utility providers!

I can also give you some good ideas for meals, which are cheap and will keep you pretty healthy – survived uni eating them anyway. (I was at uni a few years ago now and price of living has gone up, so things might not be quite as cheap as I say below. The principles of the pricing in the meals are the same though so stick to them and you should be fine).

Breakfast

Cereal’s the best thing – just buy a massive box of own-brand and you’ve got all of your breakfasts sorted for at least three weeks.

Crumpets and toast are good if you want a change.

• You can buy the cheapest own brands here because you’re heating them up. Think about it – bread gets dry and crisps over whether it’s cheap or expensive, which is what gives toast/crumpets their taste, so the brand’s quality really makes no difference at all

Dinner

Make your own sandwiches and bring them into uni/college.

• This seems like an obvious one, but for a few quid you can buy enough bread and fillings to last a week. If you buy a sandwich when you are out and about, it will be nearly £3 for just one meal
• I found the best sandwich filler to be cheese – a packet costs around £3 and lasted me for two or three weeks of sandwiches/teas (grating it rather than slicing it makes it last for much longer as well)

Also, look out for offers on things like Gingster’s Steak Slices as well – they are poor quality food, but are a good treat that can be used for dinner and tea.

Tea

Pasta – this can be ridiculously cheap if you do it right.

• Buy the cheapest own-brand pasta as you can find (as it all tastes the same), along with some pasta sauce and the biggest bag of frozen ‘mixed vegetables’ available
• For example, Sainsbury’s used to sell pasta for 7p a packet, sauces for £1 each and a big bag of mixed veg for £1
• Put the vegetables in first (as they always take longer to cook), and then add as much pasta as you want a bit later. Then just leave them to boil together for the time recommended for the pasta 
• You’ll need to play around with this a bit to get the timings right (so the veg and pasta are both ready to eat at the same time)
• Leaving the hob on, tip the pasta back into the pan and pour in as much sauce as you need (I went for half here and put the remainder in the fridge, where it will keep for a few days). Keep stirring for a few minutes – this is just to warm the sauce up really – and then you can eat it. The whole process takes about 15 – 20 minutes, so the meal is quick to make as well!

Pasta bake – this is a good meal when pasta bake sauce is on offer.

• Just buy a packet of the same pasta as above and follow the cooking instructions on the back of the jar
• You can buy different flavours that include meats etc, which really helps to bulk up the meal
• You want to cook all of the sauce at once and put loads of pasta in the baking tray. Once it’s cooked, you should have two or three meals worth of food here (depending on how much pasta you used), so keep what you don’t want in a sealed contained in the fridge for later
• This won’t last for too long, but I found that it was fine for about two days after cooking it. I wouldn't leave it any longer than this though, especially if you've cooked meat with it

Jacket potato – another really cheap meal here.

• Buy a packet of potatoes (Sainsbury’s used to sell 4 for £1) and the required number of fillers (i.e. Sainsbury’s sold cans of own-brand baked beans 15p each/tins of tuna for 35p each)
• Bake a potato (the easiest way to this is in a microwave, so just Google it if you don’t know how) and use a whole tin of the ‘filler’ to go with it – this fills you up way more than it sounds, it’s got almost no fat in it whatsoever (unless you go for tuna and mayo) and you get loads carbohydrates and protein (especially if you use tuna and mayo)

Burgers.

• Buy some frozen burgers (try not to go for the very cheap ones here), some buns and whatever else you want like cheese, salad and sauces
• Make your burgers and eat them with a few chips/a salad to bulk the meal up
• As with everything else, try to buy the biggest bag of frozen chips as you can
• You should be able to get two or three meals out of this for about £3 - £4

Spaghetti bolognaise – this might sound expensive, but it’s surprisingly cheap and gives your body all of the needed protein, carbohydrates and fat (you need some fat in your diet to be healthy, so never cut it out altogether).

• Buy fresh mincemeat (don’t buy the very cheapest stuff here), along with some sauce and the cheapest own-brand spaghetti you can find
• I used to buy around 320g of Sainsbury’s Superior mincemeat for around £3.50 (it changed slightly every week) and split it into thirds. I then put each third into a plastic sandwich bag, put all the bags in a sealable container and froze them – defrosting individual portions of meat as a needed them
• Bolognaise sauce is actually pretty expensive in supermarkets, despite it being almost exactly the same as pasta sauce. Unless you really want it or it’s on offer, I recommend that you just buy normal pasta sauce. I found that Sainsbury’s ‘chunky vegetable’ sauce worked the best for this meal. It was also £1 a jar, which gave me three meals worth of sauce.
• Using some sort of cooking oil (again, own-brands are fine for this), fry the mincemeat by referring to the cooking instructions on the label
• Be careful here if you’ve never fried meat before – common sense should tell you can get really ill from undercooking it. I suggest that you ask someone or Google it when you try this for the first time
• Towards the end of the meat’s cooking time, tip as much of the fat and oil away as you can (which makes the meal much healthier) and pour as much sauce as needed onto the meat. Stir it in and just leave it simmer for the remainder of the cooking time (stir it occasionally so the meat doesn’t burn onto the bottom of the saucepan)
• I used to pour about a third of the jar here because I split the split my mince into three portions – however you decide to do it, try to make sure that you have enough sauce to go with all of your mince for the week’s allowance
• Also, don’t pour the fat down the sink’s drain as this will block it after a while (the fat collects in the U-bend) – tip it into the bin instead

And that’s it really. This is the best advice and tips that I can give you – just use your brain and try remember these three rules:

PRE-PLAN 21 MEALS A WEEK

BUY EVERYTHING IN BULK

AVOID IMPULSE BUYS

Face off: the great white shark vs the killer whale

Our oceans are full of predators, ranging from tiny carnivorous fish to poisonous snakes; from poisonous snakes to electrocuting eels; from electrocuting eels to murderous dolphins. In short, predators are everywhere and none are more feared than the great white shark and the killer whale. Both of these animals are titans – huge animals that can hunt and kill almost anything they want to (and yes, humans are included). But which of these is the top predator? Which of them would best the other in a fight?

The great white shark, Carcharodon carcharias, is one of the most feared animals in the oceans. The sharks often hunt by taking advantage of their huge strength, ambushing the seals they hunt from underneath while they rest on the surface. Unfortunately, surfers resting on their boards can look very similar to seals from underwater, which is believed to be the main cause of great white shark attacks on humans.

I’m sure many of you are thinking that this would be the great white. And why not? Great whites have been known to kill humans and there is a huge ‘fear culture’ around sharks after Peter Benchley’s Jaws was televised in a film. You would be wrong, however, and there is a case that to show that it is in fact orcas that rule the oceans.

In the first instance, you have to remember that orcas are social and hunt in packs (which has actually earned them the nickname of ‘the wolves of the sea’). Obviously, this provides killer whales with a huge advantage over the solitary great white and orcas can bring down prey much larger than themselves. In fact, orcas have even been known to go after small female sperm whales (which are actually the largest predator alive), so picking off a lone great white shouldn't be too much of a problem for them!

Like humans and other primates, killer whales are extremely social and live most of their lives in tight-knit social groups of close family members. To prevent the inbreeding that this would inevitably lead to, male orcas usually leave their maternal pod once they sexually mature and actively seek another pod to live with for the rest of their adult lives.

Secondly, you have to consider the intelligence of killer whales, which are part of the same family of oceanic dolphins (Delphinidae). All of the members in this family are extremely resourceful and have been seen to use complex, highly sophisticated tactics while hunting their prey. In fact, killer whales have actually been observed practicing to hunt (click here for more information) and it is one such tactic that leaves little doubt that orcas are hierarchically above great whites.

As you may or may not already be aware, orcas have different cultures (in much the same way as humans do) and different pods in various locations around the world specialise in hunting certain animals. Common examples of their sources of prey include fish and water mammals, such as seals. But it is the pods that specialise in hunting sharks that are really relevant for this post. Such orcas have realised and taken advantage of two very simple aspects of shark anatomy:

• Firstly, most species of shark go into a hypnotic state of sleep called tonic immobility when they are turned upside down
• Secondly, sharks have to keep swimming in order to breathe and, as soon as they stop moving, water ceases flowing through their gills and they begin to suffocate

Since great white sharks have to keep swimming in order to breathe, they have developed a remarkable method of sleep where they rest each half of their brain separately. This allows the neurotransmitters in their brain to recover to normal levels after waking activity, while simultaneously allowing the shark to keep moving and remain alert for prey and danger.

By taking advantage of these two simple facts, orcas can kill sharks extremely easily and with very little risk of injury to themselves (i.e. the sharks can’t fight back). To do this, orcas take advantage of their extreme agility and ambush sharks from above. As they near the unassuming shark, they bite it just above their dorsal fin and use their strength and body weight to roll the shark upside down, meaning that it falls asleep and stops struggling. Then, it’s just a simple case of the killer whale holding its breath while it waits for the shark to suffocate and die!

This tactic is merciless and brutal, but it is extremely effective and scientists have actually seen killer whales using it on great whites off the coast of California! What is also interesting, other than orcas being able to kill great whites so easily that is, is that great whites (like many species of shark) release chemicals called ‘death signals’ into the water when they are killed. These signals drive off all other great whites for miles and, for many years, scientists were baffled by why the massive predator suddenly vanished from Californian waters. It was only when they realised that the exodus of great whites coincided with the seasonal arrival of a certain pod of orcas from Antarctica that they put two and two together and began to observe how the two predators interacted. Just imagine their surprise!

Brief hiatus

Hi!

As I'm sure you've undoubtedly noticed, there's been a a significant lack of new posts on here lately. This is mainly because things have been pretty hectic recently and, for the time being, it's looking like my free time is going to reduce even further! Due to this, I'm announcing (rather regretfully) that I'll be taking a short break from writing on this blog.

I plan for this break to continue until things have settled down a bit, which (for the moment) I'm hopeful will happen fairly quickly. Thus, I'm expecting to resume posting on here within the next few months and already have loads of great posts planned out for you so be sure to check back soon!

All the best,

David

Short Alzheimer's disease survey

Hi all!

I have a friend at university who's conducting a research project into various diagnostic methods for Alzheimer's disease. As part of her project, she has to gather peoples feedback on such testing methods and has created a questionnaire in order to do this.

The questionnaire (which is anonymous) is very short, being formed of 9 multiple-choice questions, and will take no more than a few minutes of you time. Please help her out by taking the survey and I'm sure she would be grateful for your help!

Thanks,

David

THIS PROJECT HAS NOW BEEN COMPLETED. THANK YOU TO EVERYONE WHO TOOK THE TIME TO COMPLETE THE QUESTIONNAIRE.

Antlions: the truth behind Star Wars

Anyone who has ever seen The Return of the Jedi will be familiar with Luke Skywalker’s and Han Solo’s plight as Jabba the Hutt attempts to feed them to the sarlacc, which lurks in the bottom of the Great Pit of Carkoon. What might surprise you though is this isn’t far from the truth and many insects live in very real danger of coming face-to-face with such a creature, which is known as the antlion. 

As their comparison to the fictitious sarlacc suggests, antlions are ambush predators and are fairly common worldwide. In fact, they are found in almost every dry, arid environment and around 2, 000 species have been described so far that belong to the family Myrmeleontidae. Like many insects, antlions have a complex life cycle and pass through a larval form before they finally mature into adults. Due to this, the term ‘antlion’ is usually reserved to the larval form of the insect (which are sometimes called doodlebugs due to the spiralling trails they leave in sand while looking for a suitable place to build their trap), as an quick way to identify the form of the insect. 

Just like the sarlacc is, antlions are terrors and are capable of eating almost any arthropod that is unlucky enough to fall into one of their traps. Thus, their diet consists of a variety of insects that ranges from ants (obviously) and termites to small spiders! How their prey is caught however, depends on the exact species of antlion and their surrounding habitat, meaning that they could be lurking in foliage, hiding in the cracks in rocks and bark or be waiting in especially dug pits. 

Unusually among insects, antlions lack an anus and store all of their waste inside their bodies until they undergo metamorphosis (where it is discarded with the remnants of their cocoon).

It is the species that dig pitfall traps in sand that are particularly renowned however, and much research has been carried out into their trap-building behaviour. Typically, antlion pitfall traps are about 3 inches wide, 2 inches deep and are dug in finely grained, loosely packed sand. This criteria allows an antlion to create a steep, treacherous pitfall that their prey struggle to escape from once they've fallen into it as the walls crumble beneath their feet. To make their escape even harder, the antlion will then toss sand at the struggling insect to create a mini ‘landslide’ that helps to drag the struggling insect further into the hole. 

And once the insect has reached the bottom of the pit, it's all but game over and the antlion grabs it in its powerful mandibles, injecting deadly toxins and acids into its prey via several long spines that project from its hollow jaws. The antlion, which is firmly anchored in its trap by forward-facing bristles on its legs and body (that prevent it being dislodged and pulled from the pit), then holds its prey still until it has died and sucks the fluid ‘mush’ from the insect - feeding in same grotesque manner as spiders do. And, once the antlion is full, it throws the withered husk of its prey from its trap in the same way as it tosses sand and sets about repairing its walls. 

Antlions can remain in this larval form for up to 3 years, depending of course on the exact species and the amount of prey that is available, before they encase themselves in a cocoon of silk underground. Here, antlions undergo a remarkable process called metamorphosis where they change into their large, adult form over the period of about a month. Once their transformation has finished, the insects emerge from the ground, wait for their bodies to dry out and harden, and take to the air in search of mates.

Depending on the species, antlion damselflies can vary from being fairly small with 2cm wingspans to being much larger with wingspans of 15cm! Adults are much bigger than the larval form and show the greatest difference in size in any holometabolous insect (one that completely changes form via metamorphosis).

Adult antlions are sometimes are sometimes called antlion damselflies (despite having no relation to the damselfly family), and, depending on the species, vary between remaining as fierce predators or switch their diet to eat pollen and nectar. As their nickname suggests, the adult form look similar to damselflies although they can easily be identified by their extremely long, clubbed antennae and very narrow wings. 

Oddly, antlion damselflies are rarely seen in nature because they are usually active in the late evening and are poor flyers so (rather ironically), are very vulnerable to predators. They can be a real nuisance in desert areas however, where they are more abundant, as they tend to swarm and can deliver a mildly painful bite to any humans that they land on!

So, you might agree then that antlions are interesting insects in their own rights - being such fierce and efficient predators - but, considering they are the inspiration behind one of Star Wars' most famous aliens, they become even cooler and are definitely well worth knowing about!

Round & round the straight line

If you’ve ever switched a light on in the dark you’ll have no doubt noticed the rather strange effect it has on moths, which are soon attracted to the light and begin to spiral round it for hours. Many people wonder what causes this bizarre behaviour and, at the moment, there is no definitive answer as even entomologists (the scientists who study insects) find it confusing. 

This isn’t to say that they don’t have theories regarding this behaviour however, and there is one main explanation that is generally accepted among the entomological community that seems to have some scientific evidence. This theory is surprisingly simple and basically works off the principle that lepidopterists (the family of butterflies and moths) use light to navigate when they are flying. 

Like many insects, moths have very poor vision that is mainly used just to detect light and movement.  Most of the information about their surroundings actually comes from their highly developed antennae, which provide them with an incredibly sensitive sense of smell. In fact, the antenna of male moths (pictured above) are so sensitive in some species that they can detect a single molecule of a female moth's sex pheromone in 1 cubic yard of air - allowing them to smell the moth from 11 kilometres away!

So, to start at the basics, there are two fundamental responses that all types of life (that are capable of detecting photons) have in response to light – they either respond positively to it and move towards the source (positive phototaxis) or negatively and flee from it (negative phototaxis). Lepidopterists are known to be the former, which explains why they converge on sources of light (such as bulbs). 

And while this appears to make sense so far, it is actually confusing to many scientists – why would an insect that is vulnerable to predators move towards a light source and make itself more visible? In fact, logic suggests that moths should actually show negative phototaxis and head towards the darkest areas they can find – they do have drab colours for camouflage afterall! 

However, the idea that lepidopterists use light for navigation helps to explain this and gives a plausible reason why they are in fact attracted by ambiance rather than repelled by it. The idea is simple and suggests that lepidopterists use the brightness of the lights in the sky (i.e. the sun, stars and moon) to calculate how high they are flying and use the angles that these lights hit their eyes to determine their direction. Thus, they think that because the lights are getting brighter, they are actually getting higher in the sky (which generally makes them safer from many of their predators, such as spiders, which live amidst foliage). 

So although this might seem like a bizarre explanation for why moths are attracted to light, remember that moths have evolved over millions of years in an environment where the brightness of the night sky has scarcely changed. It is only recently that humans have invented and built all of these streetlights and exterior lamps that are confusing them! Essentially, all the light we produce at night is hijacking their complex and highly evolved navigating systems because they now get much close to sources of light than they are expecting to! 

This concept also explains why moths end up spiralling round bulbs for hours at a time and, basically, because the stars and the moon are so far away from us, their light hits moth eyes in parallel to the horizontal axis of flight. Thus, moths have evolved a system where they use the information that this light provides to work out whether they are turning or travelling in a straight line. (Think of a cross where the flat line represents direction and the vertical one represents height).

This system is actually fairly simple and works well, until of course they become too close to a light. Once this happens, the angle the light strikes the eye at is steep enough to make the insect think that it is turning so it constantly has to compensate and turn itself to ‘return’ back to a straight line of flight. Thus, while we can see that the moth is actually flying in circles around the light, the disorientated moth thinks that it is flying in a straight line! 

And if this isn’t enough for the poor moths to contend with, many lepidopterists also believe that because moths are nocturnal (sleep during the day), being close to such a bright light actually makes them sleepy. When this happens, they are believed to enter a ‘rest mode’ and attempt to sleep, which is why they often try to land on (or nearby) the light – making it even harder for them to escape its clutches!

Scientists discover a new type of cell division!

Until now biologists have thought that human cells can only replicate using a type of cell division called cytokinesis, where a somatic (body) cell splits into two new daughter cells after doubling the quantity of DNA that it contains via a process called mitosis. Dr. Mark Burkard from the University of Wisconsin Carbone Cancer Centre however, has discovered that this is not in fact the only way! 

Since klerokinesis is a completely unseen form of cell division, Dr. Burkard and his team conducted a number of experiments to confirm that it was definitely a new type of division. Once they were satisfied that it was, they asked William Brockliss (the University of Wisconsin's professor of Classics) to help them develop the name and decided on the prefix klero-, which means 'allotted inheritance'. 

The new type of cell division, called klerokinesis, appears to occur in somatic cells that already have more DNA in them than they should and results in the production of two daughter cells that actually have the correct number of chromosomes in them! 

Although cells containing more DNA in them than they should may not sound like a big deal, it is and many cancers and diseases such as Down’s Syndrome are actually the result of this extra genetic material. For example, about 35% of all pancreatic cancer cells and 14% of breast cancer cells have three sets of chromosomes in them rather than two! 

Dr. Burkard and his colleagues believe that klerokinesis may actually be one of the body’s emergency ‘back-up’ defences to eliminate cells with too much genetic material in them so that they don’t build up in the body. This hypothesis appears to be supported by the results of his research, which found that 90% of the cells that he had purposely tried to produce with three chromosomes instead of two in them (as part of his breast cancer research), divided early in the mitotic cell cycle after an unusually long rest period to produce ‘normal' cells! 

Dr. Burkard and his colleagues are excited about discovering that abnormal cell division rarely has any long-term detrimental side-effects and believe that this research could have huge implications in our war against cancer. In fact Dr. Burkard has said that he would like be able to actually push 99% of cells towards klerokinesis by the end of his research as “if we could push the cell towards this new type of division, we might be able to keep cells normal and lower the incidence of cancer”.

Beneath the trapdoor danger lurks...

Wherever you go, you are bound to find spiders. They are an ancient class of predator and have learnt to use poisons, brute force and complex webs of silk to terrorise and instil fear into animals on every continent of the world except Antarctica. 

Typically, an easy way to tell the rough age of a species of spider is by looking at the complexity of the web it spins and the general rule is that the more elaborate the web, the younger the species of spider. This makes sense really as it would be expected for more complex structures, such as web scaffolding patterns, to take longer to evolve! Thus, the infamous tarantulas, which use silk only to line their burrows for warmth, are among of the oldest species of spider on the planet. 

Trapdoor spiders are another ancient lineage of arachnid, which is suggested by the simple manner in which they use silk. They use silk for the same purpose as many more ‘modern’ spiders since they rely on it to convey vibrations to them to show that prey is nearby, but do not spin it into complex webs. 

There are more than 500 different species of trapdoor spider that have been described so far, which can be found in tropical regions all across Earth. Despite being large and looking fairly intimidating, trapdoor spiders are rarely aggressive and are not dangerous to humans.

So instead of building silk nets like many newer species, trapdoor spiders dig a deep burrow in the soil (some species make a long tube of silk instead) and spin trip-lines that radiate out from the tunnel’s entrance. The spider then lurks near the mouth of its burrow, touching its trip-lines, and waits for an insect to knock one of the threads. When this happens, the spider feels the vibration and lunges out to grab, bite and poison its prey. 

Many species of trapdoor spider take this ambush tactic a step further and actually build a covering over the hole of their tunnel. This ‘trapdoor’ is what gives the family of spiders its name and is cleverly made from materials surrounding the burrow, such as soil, vegetation and silk, so it is camouflaged perfectly with the ground! 

Species that make a trapdoor always hinge their covering at one end with thick webbing and hold it down tightly using special claws on the ends of their feet. When its trip-lines are activated, the spider flips open its trapdoor, explodes out of its burrow and drags the hapless insect back inside for its dinner! And because trapdoors are typically very large spiders, almost all insects are on their menu – with meals commonly including cockroaches, crickets, grasshoppers, beetles, moths and other spiders. 

As would be expected, trapdoor spiders invest such a huge amount of time and energy in digging their burrows that they are a very shy and reclusive species. In fact, trapdoors rarely leave their burrows at all and female spiders typically spend their full 20 year lifespan in one burrow! It is usually only males that venture out from their burrows and even then, only once they have matured sexually and are seeking a mate. Like all spiders, male trapdoors mature near to the end of their lives (which are much shorter than those of females) so are inclined to take huge risks in finding a mate before they die. 

Once a male spider has mated with a viable female, the male dies (often to be eaten by the female) and the female remains in her burrow to feed her spiderlings when they hatch. Shortly after hatching, the spiderlings venture out of their mother’s burrow to dig their own home using their front legs and specialised barbs on their fangs called rastellum that help them to move soil.

Hangovers: what are they & can we avoid them?

With Christmas and New Years over, many of us will be looking back over the festive periods to remember the glittering decorations that adorned our homes, opening our presents, spending time with our loved ones and indulging in rich, expensive foods. And of course, no memories of the Christmas holidays are complete without those of the hangover and it's safe to say that many of us will have just as vivid memories of times spent inebriated and of those nursing the unpleasant headaches and tender stomachs that inevitably followed a night's heavy drinking. The hangover is unarguably the bane of many of our celebrations and often leads to promises of “never again”. 

Of course, there always is an again and we all know full well that we’re not fooling anyone when we make that particular promise. The call to drink when we're enjoying ourselves is just too strong! So, we will all drink again and will all suffer for it again. Yet despite knowing to expect a hangover the next morning, do we really know what one is? 

The British National Health Service (NHS) recommends that men should not regularly consume more than 3-4 units of alcohol per day and women should not regularly consume more than 2-3 units. By 'regularly', the NHS means drinking these amounts on most (more than four) days of the week.

The answer to this question is in the properties of ethanol, the alcohol present in drinks, itself. Basically, ethanol is a powerful diuretic drug (like those discussed in the earlier post: 'Coca Cola: Christmas in the toilet'), and dehydrates us by making our body absorb less water. As our body becomes dehydrated and less begin to lose water, the cells that form it shrink and contract – leading to severe problems for the brain! 

This is because the human brain is surrounded by three thin membranes that are collectively known as the meninges. Thus, as we become dehydrated and the cells in these membranes shrink, the meninges contracts and squeezes our brain. It is this squeezing effect that is responsible (predominantly) for the headache we suffer the next morning and, obviously, the more we drink, the more dehydrated we become so the brain is squeezed more and we have a worse headache for it! 

Furthermore, this squeezing effect is also slightly responsible for any memories we may have lost, working in conjunction with the disruptive effects that ethanol has on the normal activities of the brain’s neurotransmitters (which leads to the associated behavioural changes and loss of coordination and response speed that are also experienced when drinking alcohol). And, as the brain is squeezed, it compresses the areas of our brain that deal with the formation and storage of memory - impairing its blood flow. This means that these areas work less much efficiently than they do normally and we end up with ‘holes’ in the night’s events when we look back on it. 

Whereas dehydration is responsible for our headaches, it is not the cause of the feeling of nausea that is also associated with hangovers. This feeling is due to another of ethanol’s particular properties, in that it is one of the few chemicals to be absorbed straight into our bodies through our stomach lining (paracetamol is another, which is why the drug alleviates pain so quickly). As well as meaning that alcohol affects us very quickly, particularly on an empty stomach, large amounts of ethanol passing through the stomach lining can leave it feeling sore and inflamed – which is also what causes the stomach ulcers that are a common symptom of long-term alcohol abuse! 

Fairly obviously then, if our stomachs are sore then they are not going to be very welcoming of food – particularly those that are heard to digest. Furthermore, vomiting the night before (which is actually beneficial for the body as it’s a protect reflex it uses to expel ethanol once it knows that much more is being absorbed than can be broken down safely), would make the feeling worse as it could itself damage the stomach lining and leave the stomach muscles strained and fatigued. 

As well as due to ethanol, the feeling of illness and lethargy experienced in hangovers are also caused by impurities in the drinks themselves, which are a result from the brewing or fermenting process. These impurities affect the body in many different ways and often require investments of large amounts of energy to break them down (which is why you should avoid mixing drinks). Due to the nature by which these impurities are created, different drinks contain different culprit chemicals. So your body might be coping, say, with those present in your red wine, but when you switch to whiskey later, it will have to start synthesising different enzymes to break the new chemicals in the whiskey down. As there are only so many enzymes that can be made at any one time (and a finite allocation of resources to use), the body ends up not producing enough enzymes to cope with either of the chemicals – meaning of course, that your hangover will be much worse! 

And so, now that you have a fair understanding of what hangovers are you might want to know whether or not they're possible to avoid. Sadly, they're not – not unless you cease drinking anyway, which let’s face it, isn't going to happen and seems a little excessive... But hangovers are possible to minimise, with surprisingly little effort. 

1. Don’t drink on an empty stomach. Eating a large meal of foods that are high in carbohydrates, such as pasta- or rice-based dishes, before you begin drinking will absorb some of the alcohol and so slow the rate it passes into your bloodstream. Likewise, drinking full-cream milk or eating high fat foods beforehand are beneficial since fat actually inhibits alcohol absorption, so less will be absorbed into your system. 
2. Avoid ‘dark’ drinks. As a general rule, darker beverages such as red wine, brandy and whiskey, contain more of the contaminants discussed above so will harder for your body to process. Instead, try drinking clear drinks like white wine, vodka and gin. 
3. If you're out and about, avoid buying ‘rounds’. Everyone drinks at different rates and have their own limits and so, by drinking rounds, you are having to match your own consumption to those around you (and let’s face it, the quickest drinkers always pressurise others to hurry up so “we can get the next round in”), which may be more than you can handle or want to drink that night. 
4. Stop drinking early. Usually, we drink to get drunk. So when we are finally drunk, we've normally got a lot of surplus alcohol in our stomachs’ that has yet to be absorbed. If you take this into consideration and stop drinking once you've reached your limit (or at least slow down), your body will have longer before the morning to have cleared the alcohol from your system and your hangover will be less severe as the result. 
5. Drink as much water as you can before bed and take a bottle of water with you. This way, you’re drinking water that will not only dilute the alcohol left in your stomach and system, but will rehydrate some of the water that you've lost over the course of the night - alleviating the crushing pressure on your brain. 
6. Try and force a ‘full-English breakfast’ down in the morning, or something similar (like McDonald's). As discussed earlier, fatty foods inhibit alcohol absorption so by eating foods such as sausage, bacon and eggs, you can stop the last ‘dregs’ of alcohol in your digestive tract from being absorbed. 
7. Avoid drinking caffeine. Caffeine is another diuretic, so although they may make you feel better in the short term, drinks like tea and coffee will only make you more dehydrated. This will not only make your headache worse, but will prolong it as well. Instead, drink fruit juices (not from concentrates if possible), as the sugars and vitamins they contain will ‘refresh’ your body and help to restore its vitality.

If you're concerned about the effects and dangers of alcohol or want more information, click here to be taken to the NHS' alcohol help and guidance pages.