Researchers and dog behaviorists have several theories about why dogs like having their bellies scratched. It feels good. It shows they trust you
When dogs roll over on their backs, they could be asking for a belly rub or they could be doing it as a sign of submission.
The act of being touched or petted feels good to a dog. Just like people like to be touched by those they love, animals crave physical contact from members of their pack.
Dogs also expose their bellies as a sign of submission, making themselves vulnerable to show that they’re not a threat.
In a submissive dog, you might notice the ears are back, their eyes are squinty or very wide open and averted from your gaze. They might be yawning or have their lips pulled back in a submissive grin.
If you see any of those signs, leave the dog alone. You’ll only stress them out more.
What Science Says About Submission and Playfulness
Researchers concluded that none of the rollovers were signs of submission, but were used primarily as either offensive or defensive tactical maneuvers during play. All the dogs used in the study were friendly and used to playing, so their rollovers were used to block playful bites and tackles or to get into better positions to wrestle or instigate play.
Always let the dog make the decision about a belly rub. If they come close to you and flip over, relaxed, that means they are ready for some petting.
Instead, find that spot they really love — maybe behind the ears or at the base of the tail — and watch everyone’s stress levels drop.