The belly rubs that we give to our pets are fun and adorable, but there's more to it than that. When an animal presents its belly to you, it represents a sign of submissiveness or trust. Depending on your relationship with a dog, showing their tummy either means that they trust you and want a belly rub, or that they're submitting to you (in which case you should approach them in a friendly but respectful manner). Cats usually show their bellies as a defensive gesture, so most will only tolerate a brief belly rub before attacking.