Flies rub their hands together for a very specific reason. Their cleaning ritual is so thorough and meticulous that a University of Arizona study even recommends using them to teach kindergartners the importance of hygiene.
This might seem counterintuitive given their insatiable appetite for filth, but grooming is one of a fly’s primary activities. It gets rid of physical and chemical residues and clears their taste sensors.
Flies have poor eyesight
Flies may have a bad reputation for being dirty creatures, but they’re actually quite clean. Flies use their compound eyes, antennae, and bristles on both legs to sense the world around them. It’s important that these parts of the fly remain clean, so they can function properly. When a fly lands on something sticky or greasy, it will rub its front legs together to remove the dirt and grime that has collected on them. This process is called grooming and is a vital part of fly behavior. It gets rid of physical debris, as well as chemical detritus that can interfere with their senses and prevent them from smelling or tasting their surroundings.
The rubbing process isn’t just for the front legs of the fly; it also takes place with its head and wings. It’s a cleaning ritual that all flies engage in. A University of Arizona study even used a fly as an example to teach kindergarten children about proper hygiene!
You might have noticed that a fly walks all over your food and stops periodically to rub its front legs together. There’s a reason for this; flies can taste foods with their feet! They have special sensory hairs on their feet that help them detect different flavors. Flies can tell if a food is sweet or sour, for instance, or whether it’s tasty or foul.
When a fly is walking on hard food, it will rub its front legs together to clear out any dirt or debris from the taste sensors. This helps them better discern the hard or soft regions of a meal so they can consume it effectively. Likewise, if it can’t get at a particular section of food, it will vomit saliva over that area to break down the food and make it easier for them to eat. This is why flies often walk all over your food; they’re trying to find a spot that has sufficiently decomposed so that they can start eating!
Flies have sensitive feet
Flies aren’t exactly household names, but they can do a lot of damage. They’re blamed for everything from diarrhea to shigellosis, and for transmitting diseases including tuberculosis, anthrax and food poisoning. Their minuscule eyes and brains, though, allow them to evade almost every swatter you throw at them, thanks to a bit of fast, sophisticated visual processing and a few neural quirks.
It might seem strange for a creature that lives on dirt and other filth to spend so much time preening itself, but fly researchers have discovered that it’s vital to keeping those creepy little claw-things clean. Flies rely on their compound eyes, antennae and bristles on both legs and bodies to sense the world around them, so it’s important that these delicate sensors stay shiny. Even a small smear of grime can interfere with movement and provide a foothold for deadly microbes like molds and fungi.
When a fly lands on a wall or ceiling, it saves energy by walking with only three feet attached at once. It also gets a grip on the surface with sticky hairs and claws that look more like a set of bull’s horns than a fly’s typical, flat spatula (shown in this false-color scanning electron micrograph). The pads at the ends of those hairs increase the contact area of the foot, and the claws are shaped to pry loose anything clinging to the wall or ceiling.
But all that clinging comes at a price: the better a fly sticks to a surface, the harder it is to get unstuck. So Stanislav Gorb of the Max Planck Institute for Metals Research in Germany has been studying a lot of fly feet, using electron microscopy, high-speed video and clever devices that measure forces. He and his colleagues have found that a fly has four ways to detach its foot: pushing the foot away from the body, which tends to scrunch up the pads and pop them free; twisting the pad loose; planting the claws and prying the foot up; or just yanking its foot off the surface with brute force.
Flies communicate with one another
While we may view fly rubbing its hands together as a villainous gesture, it’s actually quite important for these insects. They use their hands—as well as other parts of their bodies—for a number of tasks, including sensing odors and tasting food. They also groom themselves, communicate with one another through vibrations, and keep warm during cold weather.
You’ve probably noticed a fly rubbing its “hands” before it heads towards a delicious meal, but you may not have understood why it does this. In fact, flies rub their front legs together to clean them. Tiny particles from the things they land on get stuck in the hairs on their legs and wings, so rubbing them together removes these substances. This is a regular part of a fly’s grooming routine, and it helps them sense their surroundings better.
Flies have very poor eyesight, so when they smell or taste something, it’s important that they can make out the details. They also have very sensitive feet, which means they need to be able to feel the surface they’re walking on. The rubbing of their feet help them to do this, and it also keeps them clean.
Another reason a fly rubs its hands together is to cool itself down. It does this by allowing heat to dissipate from its body, which makes it more effective at absorbing other resources. In addition, this process allows a fly to stay warmer for longer, which is especially helpful in colder temperatures.
When a fly smells food, it uses its taste sensors to find out whether the food is hard, soft, or decaying. This is how a fly knows whether it’s safe to eat and where to start. If the food is hard, it’ll try to lick the food to taste a soft area. If it’s soft, it will move to a different area of the food and continue smelling it.
If the food is decaying, it will have an odor that attracts flies. Flies use their front feet to smell this odor and determine whether it’s safe to eat. If the odor is strong, they’ll move away quickly to avoid getting sick.
Flies keep warm
Flies are known for rubbing their hands together, which can appear to be a menacing gesture. However, they are not plotting anything evil, and their rubbing movements serve a variety of purposes. For one, it helps them keep their legs and feet clean. This is because the bottom of their legs are covered in tiny hairs that help them sense their environment, and rubbing their legs against each other helps remove any dirt or debris from these hairs. It also allows them to better smell their surroundings, which is important for finding food and attracting a mate.
Another reason why flies rub their hands together is to check the condition of their limbs. This is because flies are cold-blooded, which means that their body temperatures are dependent on the temperature of their surroundings. If the surrounding temperature is too cold, it will be difficult for them to fly or eat, so they must keep their legs and wings warm in order to be able to move around freely. By rubbing their hands together, flies can ensure that they are in good condition and ready for flight or fighting.
In addition, flies often rub their hands together to communicate with other flies. They can do this by detecting vibrations that other flies emit through their mouths and legs. This way, they can tell if other flies are in danger or are nearing a food source. This is an important part of the fly’s communication system, and it can also help them avoid conflict with other flies over resources.
Despite being a nuisance, flies have many interesting traits that make them unique and fascinating. Their poor eyesight and sensitive feet allow them to be a great tool for finding food, while their hand-rubbing behavior is a useful way of communicating with other flies and keeping themselves warm in winter. Although their rubbing behavior can be irritating for humans, understanding the importance of fly hand-rubbing can help you get rid of them and keep them away from your home.