Ben comes to bed at the same time I do (we go to bed early to get to sleep before the snore machine hubbby gets there!). He starts on hubbys side of the bed, curled up next to me, then he'll spread out as if trying to make sure hubby sleeps elsewhere. hubby will shove him to the center of the bed without waking anyone up, and in the morning, Ben is right back curled up next to me. Luckily, I get his face in my face...hubby gets the other end!
Now, if hubby wakes me up with snoring, I just go to the guest room. Ben will follow about 5 minutes later
. He can't even sleep in a different room than me. He'll come into the room with this sleepy look in his eyes like "Mom...Dad woke me up with his snoring too, can I sleep in here?!" Ben snores too, but not like his 'Dad'!
So, to answer your question, yes, the dogs do move around alot in the night. Maybe he gets too warm in that spot...our dogs will move around alot more in the summer...preferring to sleep on the floor instead of the beds (or on the couch in front of the AC vents!).