Bears don’t poop during hibernation. You might wonder, “How do animals keep in their poop when they hibernate?” Before an animal goes into hibernation, they will eat a lot to sustain them until they wake. So, where does all the food go? Bears keep their food in by eating grass and twigs, creating a plug or stopper in their bowels. With this stopper, they can sleep continuously without having to poop. However, once they wake up, it all comes out.