Because if they didn't they'd fall over.
He wanted to have webbed feet.
They lay down on their backs and put their legs and arms toward the sky.
Bach in the saddle again.
They're not falling for that again.
Benot B. Mandelbrot
They grab the stack of un-signed adoption papers, stand on top of them, then proceed to change the light bulb.
If it didn't stand on any, it would fall over.
Because if he lifted up both legs it would fall over!