[NSFW] What animals besides humans masturbate?

There’s a joke that asks. Why do dogs and cats lick their private parts?” The punch line is “Because they can.”

But to be fair to our canine and feline friends, we all know thay do it to keep themselves clean. Their systems are designed to process what they ingest in the grooming. And they definitely don’t do it to pleasure themselves.

We humans just about all do pleasure ourselves. But are we unique in doing that? Cats and dogs could, but don’t. Their mating instincts are ruled by pheromones and without those being present, they have no interest in sex. What animals share the nasty dance habit with us human beings?