Why do insects like ants not get broken legs when falling from a distance like humans?

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I saw an ant on the table today, I brushed it aside and it fell on from the kitchen table to the floor, around 3 feet. I then saw the ant continue to move forward as if nothing happened. I feel a human may potentially break a leg if falling from a comparable height. So I’m curious, why did the ant not break any legs?

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Anonymous 0 Comments

If you’re falling from a tall height, there are a few things that’ll decide how bad the landing hurts. If you’re falling from *very* high up, you probably have time to think about all of them, lucky you.

First is how fast you’ll be going when you land. Gravity pulls us all down with the same acceleration (more or less), but the faster you go the more the air pushes back on you, and eventually those two forces balance out – any faster and the wind pushes you back enough to slow you down, any slower and gravity speeds you back up. This is called your *terminal velocity*, and it’s the fastest you’ll ever fall under normal conditions.

An ant has a terminal velocity of about 4 miles an hour. A human has a terminal velocity of about 124 miles an hour. If you fall from high enough up, you’ll hit the ground going a lot faster than the ant will.

Why does speed matter? Because the faster you’re going, the harder it is to stop. And size matters here too – a huge thing going very fast is harder to stop (has more momentum) than a small thing going very fast. When you hit the ground it *will* stop you, and your body’s going to take the brunt of the force it takes to set the speed of something your size back to zero.

And last, some creatures really are just built different. An ant is really tiny (so the message that “hey we’ve stopped” travels through its body pretty quickly) and it’s very sturdy (it’s wearing armor!), so it can absorb the shock of the fall pretty easily. A human’s much bigger (so your feet say “hey we’ve stopped!” while your torso says “nope, still falling!”) and a lot squishier (your bones are pretty strong but they’re on the *inside!*) so it’s easier to injure yourself when stopping at the end of a big fall.

This mix of size, build, and speed means that different creatures will fall and land differently. There’s a great (and horrible) adage from J.B.S. Haldane, a biologist:

“You can drop a mouse down a thousand-yard mine shaft and, on arriving at the bottom, it gets a slight shock and walks away. A rat is killed, a man is broken, and a horse splashes.”

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