Some people might remember the musical group that had the name "Three Dog Night." It was an old saying that referred to how cold of a night you had. Apparently the more dogs that joined you on the bed at night meant it was a pretty darn cold evening.
Gracie must feel every night is cold as she is always snuggled up next to me. In the winter we have have a couple of cats on the bed as well. When I went out and purchased a bigger bed so I might be able to straighten out my legs at night I found that it was no help at all. They all want to snuggle no matter how much room there is on the rest of the bed.