coons,oppossums,skunks,weasels,foxes and many other critters have the desire to gnaw on wood and bones and they are full of calcium and other things that animals crave,it is a nessecity for them to keep their teeth small enough so they can eat other wise their teeth would grow so long that their mouths would be blocked and they would starve to death.their are many critters around our homes at night,that is why some nights your house dog wants to go out ten times and others he will sleep all night without a peep