Re: because...

they keep them in the basement usually, until the sun goes down. Then when all the real staff goes home, they replace them. Oh, they look human all right. At least in the dark.

They have special shoes, special "creeping" shoes they wear, so they can slip in your room at night when they think you are sleeping.

They also communicate via insect noises to each other.

I can't say anymore about it. Too dangerous.