Well I've tried destroying them, but they simply pop up again as if nothing had happened to them. I tried taking an arm off one of them to see what would happen, but it faded away when the body did, and reappeared on it as if nothing happened. Then I tried turning them invisible, but that only worked until they would blink out of existence and then back again.

All in all... I have no idea what to do with the bodies. I don't even know if they would disappear for good if you fed them to one of the monsters.