Why can't you hit the fly?

In the kitchen or restaurant, you can always hear some annoying "buzzing" sounds. Strangely enough, this fly is actually not small, dark black with a bit of red or green polarization, so it should be relatively easy to hit.

But in fact, a "lively" fly can usually fool a person or a group of people. I still remember the scene of my parents and I chasing a fly in the living room, each with a fly swatter.

We can't hit flies because flies have very strong avoidance behavior, which is because they react very quickly. And in the eyes of flies, we humans are even very slow.

The same time, in our eyes, is moving at a constant speed. But from the fly's perspective, each turn of the second hand is slower than that of a human. From the turtle's perspective, it is faster than the original speed.

The main reason why different species have such different responses to time is because of differences in vision.

The brains of all animals, including humans, extract individual images from the eyes at a fixed frequency per second, and then string them together to form a continuous picture.

The speed at which the brain receives images is called the "flash fusion frequency." Generally speaking, the smaller the species, the higher the flash fusion frequency, because small creatures need more reaction time to avoid being preyed upon by their predators.

Normally, our eyes can capture 60 frames per second, which means an average of 60 flashes per second.

The fly's eyes can receive 250 frames of image information per second, flickering an average of 250 times per second.

Are you surprised? Flies are four times more capable than us in this regard. For example, a fly can react in just 0.25 seconds to something that takes a human 1 second to react to.

So from the fly's perspective, each of our basic attacks takes too long to happen, and the opponent can already predict where we are going to hit.

The fly's eyes have an extremely wide field of vision, with a nearly 360-degree surround view, and can see dangers coming from behind.

With these conditions in place, it will be a piece of cake for the fly monsters to avoid our slaps.

Rub your hands leisurely

But this alone is not enough. Even if you can receive so many frames of images per second, you still won’t survive more than five minutes without a more agile and flexible body.

Therefore, the fly's highly maneuverable wings are also a very critical part of the entire avoidance behavior.

A mature fly monster flaps its wings approximately 200 times per second , and more when evading predators.

When they flap their wings, they create leading-edge vortices on both sides of the leading edge of the wing , a structure somewhat similar to a tornado. This vortex allows the wing to generate enough lift to keep the fly in the air.

The "engine" behind the flies' ability to perform such difficult aerial acrobatics is also not to be underestimated. This involves the two flight muscles they use for navigation.

For these lovely flies, the main muscles that flap their wings are not directly attached to the wings, but grow on the inner wall of the chest cavity .

This group of muscles is the power muscle of flight. They can be activated on their own and do not need to be controlled by the central nervous system. They are specifically designed to provide tremendous energy for the fly's flight.

There is also a set of muscles attached to the base of the wing, which is a set of small control muscles. Although the force is not strong, the speed is very fast. It can fine-tune the rotation axis of the wing to affect the height and angle of flight.

This group of tiny steering muscles is crucial to the maneuverability of flight. Although it only accounts for 3% of the total weight of all flight muscles, it is enough to allow the fly to complete all the steering movements it needs during flight.

With these two engines, and the fact that flies have a reaction ability that is four times stronger than ours, it would be difficult for humans to fight them.

However, since flies have time to predict their movements, when we swat flies in the future, we cannot just aim at them. We have to predict the flies' movements and swat them around them. If we are lucky, we can achieve a pleasant "headshot" effect.