Why do flies have such good reflexes?


The only explanation I can come up with is that time moves slower for them

In: Biology

They’re very small, and have the same complexity of nervous system, but smaller and more sensitive.

So they can notice an attack before it lands from the wind that comes before it

Firstly, flies are 100% reflex. There’s no decision or second guessing; *everything* they do is the instinct of the moment.

Secondly, their eyes are *way* closer to their brains and wings than any bit of you is to any other bit. That distance matters, because it takes time for signals to get across it. Not much time, but it adds up.

OK, so another poster said that flies are 100% reflect, we don’t actually know that for sure. Your initial supposition is closer to the honest to god truth. We see in about ~30 frames per second, a fly is 100 frames per second. They literally see you before you are able to see your own actions. So if something is moving very quickly, like me trying to swat at a fly, they can see 3x the amount of frames I can (and have the neurology to process the input) then my swinging arms will appear slower to them.

This ability is directly related to their ability to fly. Birds tend to ‘see faster’ than we do as well. Consider a fly during a rainstorm. They can literally turn themselves around, grab the water, and spin around again dropping the water below them. You need to see very quickly in order to do that.

Flies show some cursory ability to make informed decisions, if you have any decision making capacity at all, you aren’t 100% reaction. That is an old way of looking at insects, insects probably have far more advanced neurological capabilities than we give them credit for – it is just that our experience of the world and their experience of the world are so radically different it is hard to compare objectively.

TL:DR – They react faster because they can see faster

evolution. Slow flies die more easily, and therefore have less opportunity to reproduce. there is tons of selective pressure, both from predators and from humans who find them annoying.