7. Back-to-Back
If you have more than one dog in your home, you might notice that they sleep back-to-back. Wild dogs tend to huddle to together for protection and warmth in the wilderness, so back-to-back sleeping is an instinctual way for a dog to show you are one of the pack.
Pups can also do this with their human pack, too! According to Dog Time, back-to-back sleeping is a way for your pup to bond with you, showing you that they can trust you 100%. So, if your pup crawls into bed with you and presses their back against yours, they’re just showing you some extra love!
From: tiphero.com