How come an ant is able to carry a piece of food that may well weigh more than its own body?



How come an ant is able to carry a piece of food that may well weigh more than its own body?

In: Biology

Because unlike humans they don’t spend half of their energy whining about the task at hand, and just get on with it.

Jokes aside, ants can lift so much weight because the amount of their overall weight/size that is muscle, is much higher than a lot of other creatures. So although small, they be mighty.

Take a column. The strength of a column (how much weight it can bear) is based on how thick it is.

Think about it this way, if you stretched it in one direction so that it was twice as wide (with the same height and same depth), this would be the same as simply having two of the original columns side-by-side. It can hold double the weight, but it also weighs twice as much.

If you stretched it in two directions so that it was twice as wide and twice as deep (but the same height), this would be the same as having four of the columns in a square. It would hold quadruple the weight but it now weights four times as much.

Last, if we stretched it in three directions (twice as wide, twice as deep, and twice as tall) it’s as if you have the four columns from above, but then another four stacked on top of it. This doesn’t add any additional strength (so it is still 4 times as strong) but it does add weight (it now weighs 8 times as much). Since part of the weight it can support includes its own weight, this large column is now comparatively weaker than the others.

This is known as the cube-square law. If you scale something up in all dimensions by some factor (e.g. 2), it’s strength increases by the square of that factor (e.g. 2^(2) = 4 times as strong) but its weight increases by the cube of that factor (e.g. 2^(3) = 8 times as heavy).

This means as things get *proportionately* bigger, they get relatively weaker, until they can no longer support their own weight.

On the flip side, as they get *proportionately* smaller, they get relatively stronger.

Going back to the column example, let’s say our original column weighs 100 pounds and can hold 400 pounds (including its own weight). That means you can put an extra 300 pounds on it (300% of its own weight)

Scale it up by a factor of 2 and it can now hold 1,600 pounds, but it also now weights 800 pounds. It can still hold more weight (800 additional pounds) but in terms of its own weight, it can only carry 100% of its body weight.

Shrink it down by a factor of 2 and now weighs 12.5 pounds and can hold 100 pounds total (87.5 pounds, or 700% of its body weight).

What does this have to do with ants? Well, the ants legs are basically like columns. They determine how much it can carry. And because of all the above reasons, an ant can carry many times its body weight simply because it is very very small.