Buddy Boy does this too!!! One day he was trying to cover his knuckle bone with lint from the carpet or such! I gave him part of a old tee shirt and he uses this all the time to cover just that one bone! And when he hid a denta bone behind the couch he checked it everyday at least once and one day it was gone so think he moved it outside. He has a stash buried outside and before he will dig anything up he will check to see if anyone is looking out at him from the house! Don't you think they are saving it for later in case they have no food - like they would do in the wild?