[troubletb]

I don't know why they do it either, but 2 out of three of mine did the same thing. I thought it was beacuse of separation, as they did it when I was not home. In total they destroyed the entire laundry room, a dinning room wall, a living room wall, just out side of my bedroom and then the wall by the door that I leave from. I had to start keeping them in crates when I was not home.
Good luck.