Funny Dog is rolling in the ground

Rumble / Dog is rolling on the ground

they’re trying to mask their scent. Grass is covered in smells, from humans, other animals, and from the environment around it. Rolling around in the grass is a way to rub those scents into their fur, which, for a dog’s ancestors, was a great way to conceal their own natural scent and be more unassuming while on the hunt for prey.