Humans have two teeth - the Milk teeth that fall off and then the permanent ones that stop growing after a while. But there are some animals whose teeth never stop growing, sometimes poking their face and even hurting them. Here we mention 8 such animals.Humans have two teeth - the Milk teeth that fall off and then the permanent ones that stop growing after a while. But there are some animals whose teeth never stop growing, sometimes poking their face and even hurting them. Here we mention 8 such animals.