Well, they help to hold the ground down. Ever since cats invented philosophy, things have been a little uncertain around here. But hippopotamuses keep everything nicely anchored. It's hard to be uncertain about an animal that weighs as much as a pickup truck. You might think elephants are busy holding the ground down, too, but you'd be wrong.
Elephants have other things to do.
The ancient Greeks used to think the muses were all women wearing translucent curtains, but scientists have disproved this theory. Now we know the muses are elephants wearing translucent curtains. It's a good question. There's some confusion about rhinoceroses. That's why people invented cans.