Wake up, go to work, seek out caffeinated beverages, get food, share food with others, store leftovers for later, and repeat. This routine sure does sound familiar, doesn鈥檛 it? With over 3.5 billion employed people worldwide following a variation of that basic routine, I wouldn鈥檛 blame you if you thought I was talking about humans. But what if I told you I was actually illustrating the day in the life of a bee? As it turns out, humans and bees have very similar lifestyles. They protect their own, work together during the day and seek the refuge of their hive at night. However, the main similarity I want to explore is both species鈥� shared love of psychoactive substances.
Psychoactive what?
Psychoactive substances are categorized as any drug that affects the brain鈥檚 functioning which can affect one鈥檚 mood, awareness, or behaviour. Now you may be thinking that you have never consumed this type of substance before, but caffeine, alcohol, nicotine, and certain pain medicines are all psychoactive substances. Now bees won鈥檛 grab a pint with their friends after a long day of work, or take ibuprofen for a headache, but they seem to have the same affinity for caffeine that our society does.
Bees drink coffee?
No, they won鈥檛 try to steal your morning brew. Bees get their caffeine dose from their own sort of energy drink, caffeinated nectar. This nectar is much less caffeinated than our typical double shot of espresso, but they will specifically seek out these plants that contain low concentrations of caffeine and after getting their first taste they keep going back for more. Several different plant species such as citrus and coffee plants (used to make coffee) contain caffeine, but bees tend to be a bit picky. Just as we like our coffee doctored to perfection, bees prefer their nectar to be concentrated with less than 1 mM of caffeine so that the caffeine鈥檚 natural bitter taste is masked by the sweetness of the liquid itself.
Caffeine exists in plants as a natural deterrent to herbivores. Plants are smart and will use caffeine concentration and localization to simultaneously discourage herbivores from eating them and encourage pollinators to visit them and do their job. At high concentrations, the bitter taste discourages animals and insects from consuming the plant and can even be lethal. The highest concentration of caffeine in plants is bound in their leaves and seeds. Luckily for the bees, the nectar and pollen are at a perfect concentration for them to get their caffeine 鈥渂uzz鈥�.
What does caffeine even do?
In humans, caffeine is a known stimulant that increases heart rate, mental alertness and physical energy, which is a very welcomed side effect. Funnily enough, bees experience a similar reaction when consuming this plant metabolite. At the right dose, caffeine improves memory retention in bees and even helps them learn faster.
It seems weird to think that bees have memories, but they do. Evaluating them is a bit easier than your traditional matching game but fundamentally it鈥檚 still the same. A study evaluating bees鈥� remembering capacity was published in the Proceedings of the National Academy of Sciences in 2004 and the tests involved showing a sample of bees a pattern and then placing this pattern at a certain distance away from a tunnel deemed the 鈥渄ecision tunnel鈥�. An incorrect pattern was placed close by the correct pattern and the bees had to decide which they were shown first. This study showed that the bees didn鈥檛 just guess which was the correct pattern but rather that they could actually remember what they were shown hence the majority continuously picked the right pattern after multiple different runs. Most of us can鈥檛 even remember what we had for lunch鈥how-offs. So, there you have it, a bee can remember things so be careful the next time you want to swat one away.
Caffeine doesn鈥檛 just help a bee鈥檚 brain; they get an added bonus that this substance doesn鈥檛 provide humans.
Caffeine has been proven to increase the expression of immunity genes in bees, lowering their chance of infection. Moreover, this psychoactive substance does not harm the bees鈥� existing helpful gut microbiota which could be catastrophic. Overall, caffeine has not been proven to affect the survival rates of healthy bees but instead increase the chance of survival of bees battling certain bacterial or fungal infections. So, caffeine is basically bee medicine, in the right dose of course. If only this was the same for us!
Now it is no secret that caffeine is an addictive substance. I am no stranger to the occasional 鈥渃affeine withdrawal headache鈥� when I don鈥檛 have time to make my coffee before heading out the door. It comes as no surprise that this drug鈥檚 addictive capacity also extends to bees. Once they discover that a flower or plant has this energizing nectar, they remember where it is and continue to visit it. They will even share this information with the rest of the colony so that they can all reap the rewards. It is sort of a vicious cycle; caffeine makes bees remember so that they are able to remember where the caffeine is.
So, I guess we do have one thing in common!
Well yes, when it comes to caffeine鈥檚 power over both human and bee populations, there is no doubt we exhibit very similar responses to this substance. We both seek it out, it makes us feel good, and if we have too much it can harm us.
These small pollinators have a pretty big responsibility: ensuring the prosperity of our entire planet and its biodiversity. They support our diets, the air we breathe and the smooth functioning of entire ecosystems. It鈥檚 no wonder they need a little pick me up every now and then. I am sure we can all sympathize.
So, the next time a bee seems to be annoying you just remember they may not have had their caffeine fix yet.
Angelina Lapalme is a BSc student majoring in Bio-Organic Chemistry at 平特五不中.聽
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