At what point do small bugs take damage from falling?

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I released a spider today and after launching it from about six feet up, which was about 72 times its height, I started to wonder about this.

EDIT: Took out a typo. I didn’t think anybody would care or notice but you know, Reddit.

In: Biology

They don’t. Their terminal velocities are too low. They just won’t hit the ground from falling hard enough to cause damage.

Terminal velocity is the max. speed you’ll hit the ground at if dropped. It’s determined by things such as gravity, air pressure, shape and density of the dropped body.

Might be different if the wind blows them into something.

In fact, things like spiders, ants, etc are found floating in the air. Like, plane flying altitudes.

Some can take no damage. This is due to an exoskeleton in some bugs. It’s also due to the [square-cube law](https://en.wikipedia.org/wiki/Square%E2%80%93cube_law). Bones and muscles increase in strength based on their cross-sectional area. This increases at a rate proportional to the length squared. Mass, by contrast, increases at a rate proportional to the length cubed. This means that as bones and muscles get larger, their strength is increasing slower than their mass. For bugs, the strength to weight ratio is much, much better than in humans. Most bugs have a terminal velocity (the fastest speed the object can fall on Earth due to air resistance) much slower than would be required to damage the bug.

If you dropped a squirrel, a person, and an elephant of the Empire State Building, the squirrel would be fine, the person would shatter every bone in their body and die, and the elephant would explode. Bigger things hit the ground harder, smaller things hit the ground lighter.

While this question is marked with a biology tag the answer really is more about physics. Lightweight objects tend to have slow terminal velocity. A bug isn’t very dense.

Now, in a vacuum, on the other hand, the answer would be different, assuming you could find a bug that doesn’t need air to live and wouldn’t just die from the vacuum alone.

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They don’t. They are so light that their terminal velocity (the fastest they can fall due to air resistance) is lower than the speed it would require to hurt them. You can drop an ant from a sky scraper and it would be pretty much fine. There is such little mass that the forces they feel when hitting the ground can’t really do significant damage.

Spiders can and absolutely do rupture their carapace and die from falling. Just the smaller they are the less likely.

Probably never. Wind resistance stops them from getting any appreciable speed no matter how high you put them.

Consider instead a piece of fluff or a sheet of paper. How high do you need to drop it before it will take fall damage? Well, doesn’t matter, it isn’t aerodynamic enough to fall fast enough to get significantly hurt.

Since i saw everyone say terminal velocity but noone explain it:

Terminal velocity is the maximum speed at which a given object falls. It is determined by the objects weight and drag coefficient.

The reason is that an object gets accelerated by gravity. While falling, it also experienced drag. However, drag is based on speed aswell. The faster you go, the faster the drag rises. At a certain point the drag and gravitational acceleration are equal and the object cannot fall any faster.

In terms of calculating this, the hard part is figuring out an objects drag coefficient and its actual relevant surface area

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The smaller something is the less they have to worry about strain from their own weight, and that also applies to falling damage. It’s because mass is exponential, and is why elephants need huge legs in proportion to their bodies and insects don’t.

I have an additional question on this topic:

What would happen if you dropped an insect from a great height, but in a total vaccuum, like those huge vaccuum hangars for space research?

Ignoring the pressure effects on the insect’s physiology, the fall would kill it, as its terminal veloocity is now infinite, right?

If you dropped a feather from a skyscraper, it wouldn’t fall any faster or hit the ground any harder. Every object has a certain amount of “lateral surface area” which creates drag via the air below/around it. A barbell or rock is dense and the air flows right around it. Bugs, on the other hand, have lots of legs, hairs, wings, shells, and other things to slow them down. Combine that with their relatively lower density and low weight overall, they are susceptible to air and wind currents much more than a human or a heavy object.

As people already pointed out, it’s about the terminal velocity.

So the better question would be:
How heavy should a small bug be to take damage from falling?

They’re too small.

As mass/volume of an object changes, its material strength does not change in the some proportion. If you double the size of an animal, its strength would not also double, because there’s more of it to move around. This is one application of the square-cube law

Small bugs have a huge amount of surface area relative to their weight, which gives them a lot of air resistance. This means that as they fall, the air is pushing back up on them to slow them down, and it slows them down so much that they can’t get hurt from falling any distance. It’s like having their own built-in parachute.

I just woke up and misread the question. I thought it said “at what point” as in how big until a bug starts taking damage

I mean, that’s the kind of thing one should worry about **before** you yeet the poor guy off of the ledge!

There are some incorrect answers here because some commenters didn’t the question. OP did **not** ask **whether** bugs are damaged by falling, they asked at what point they **are** damaged by falling.

This means OP isn’t looking for a practical answer (because typically they aren’t damaged,) but for a theoretical answer.

And that answer is, when they fall a long enough distance in a vaccuum onto a hard enough surface. The damage done to an object when it lands at the end of a fall depends on how sturdy the object is and how quickly its speed changes. If you take a particular bug falling in air at terminal velocity, the only other factor is the amount of springiness there is to the surface it falls on. Drop it onto a soft cushion and it won’t be harmed. Even rocks will give a little, but not as much, so a bug landing on a rock might be hurt.

There is a caveat that the bug might have a cushion of air slowing it down right before it lands – depending on the shape of the bug it still might not be hurt. Now let’s remove that cushion by having the bug fall in a vaccuum. Then, there is also no terminal velocity, so as long as it has time to accellerate, the bug can fall faster. Even a short fall can now kill the bug, if it lands on a solid enough surface, and if it has survived being in a vaccuum.