I remember hearing the reason behind the digging! lol Some tv program was on and I was listening to why dogs do this. They said that pets even indoor pets will dig into blankets,the rug,furniture when they are getting ready for bed.The said that hundreds of years back ,dogs lived and slept outside.Their owners or the dogs would often dig into the dirt a bit to get cooler ground and a spot for their dogs to sleep in.THey said most dogs did this automatically on their own. Even the indoor pets of today still have this instinct to dig for their sleeping spot. If it's totally true or not I dont know but it makes sense to me
Genie, Cookie & Mimi