Bunnies only bite when they are scared or angry . To stop that stay quiet around the bunny, don't move around it to quickly, and don't chase it or grab it really hard. Feed it treats like apples and bananas a few times so it will be more happy and pet it too.

Most animals bite out of fear, so show them they don't have to be afraid of you. So you need to move slowly, be gentle, bribe them with their favorite food treats.

Are you torturing them or something? Just be nice and gentle, they are obviously scared if they are biting and need to get more used to you.