Reagan does it and she does it like she's trying to dig a hold to China in 2 minutes flat. I've read that its instincts, wolves do it and so on....
I also found this on
http://twotrees.www.50megs.com/attic...a/mammals.html
"Why do dogs often turn around a few times before lying down?
We could approach this issue anthropologically. Canine culture is peculiar. There is the doggy bone-burying ceremony, which may have religious or economic significance. We are only just now developing a lexicon of tail-wagging signifiers. And cultural theorists have only begun to deconstruct dog-meet-dog sniffing.
But when it comes to the old spin-around-before-lying-down routine, there's an awfully simple explanation. Fido's ancestors did not have the benefit of spacious suburban backyards or a nice, cushy pillow in a box in which to nap. Before they could lie down they had to clear a space in which to do it. That meant flattening out the surrounding underbrush by trampling on it. Do that for a few million years and it becomes a habit. Did you ever try to break a habit?"
I think this covers the digging too.
What's even better though is when they try and bury bones indoors. Reagan will dig at the carpet and lie the bone (greenie, piece of her food or just whatever) in the hole she thinks she dug then cover it up using her nose and the invisible dirt she just dug up. I have to laugh each time I see her walk away with it still lying on the floor for everyone to see.