Do flies sleep? Well, flies are undoubtedly some of the most annoying creatures on this planet. Thankfully, their ceaseless buzzing stops at night because they take a nice long snooze, just like humans. Actually, fly sleep is similar to human sleep on many levels and this could help unravel many mysteries.
Before delving into the world of fly sleep, let’s take a moment to acknowledge that flies are more than the lowly housefly alone. They are a despicable bunch: from blowflies and horse flies to fruit flies and mosquitoes, it seems that these two-winged insects live to make life miserable for humans. Yet everything about their sleep eerily resembles human sleep.
What we know about fly sleep
Though flies can take a few short naps during the day, most of them sleep at night. Flies turn in for the night by finding a safe spot where they can sleep—like a leaf or a twig. Here, their sleep cycles through both light and deep phases. It is also known that baby flies need much more sleep than adult flies. Sleep deprivation affects fly memory and losing sleep one day results in sleeping more the next.
The similarities to human sleep do not end here. Two proteins responsible for sleep called per and tim build up in your eyes in the dark and break down in the light. These proteins are not only found in humans but in the eyes of flies and other daytime animals. Flies are affected by stimulants that keep humans awake, like caffeine, while antihistamines and alcoholic beverages make them drowsy.
Fruit flies: Unsung lab rats
Scientists admit they are still baffled about many things concerning sleep. Studying human sleep can be tricky, so the answer may lie in studying a simpler organism… like a fly. Fruit flies are wonderful experimental organisms because they have a simple genome and a short life span. Of course, it also helps that most people don’t get too upset about experiments performed on fruit flies. These teeny flies have lent a hand in many experiments over the years and in a recent study, they not only lent a hand but gave their wings.
Researchers wanted to see how challenging circumstances affect sleep. They prevented baby flies from letting their wings expand and as a result, they couldn’t fly. They also disabled the wings of older flies by cutting or gluing them. Now, before you humanise these flies too much, please take a moment to consider how many times you’ve either wished a fly dead or killed one. We rest our case. Losing their ability to fly made the flies sleep more. Researchers found that wing injury and normal wing development activated the same neural pathways. Basically, their theory is that sleep heightens brain plasticity to help the fly learn to survive despite not being able to fly. This could start to explain why some people need more sleep and why some sleep disorders occur.
Flies are teaching us a lot about human sleep. So next time you see a fly, take a moment to say thank you for the medical mysteries it is helping to solve. Then you can do what you want to it.