Shakespeare wrote that on his tombstone… Well, actually, somebody else wrote it, Shakespeare himself was out of the saga. But he didn’t want to be dug up, and said so.
Dogs don’t want anyone else digging up their bones, so they hide them. Indoors, that’s not so easy. They do the best they can, but some human always seems to wind up sitting on the hidden bone and making a scene.
Instincts are pretty powerful. No dirt, no way to dig, but they use the same motions.
I have sat on a few hidden bones in my time/