Animals Masturbate. I said it, and yes, they do.
I have compiled a list of animals that masturbate and how they do it.

Animals That Masturbate

1. Dogs

Dogs masturbate in various ways.Β They mount and thrust against other animals, people and objects, such as wadded-up blankets, dog beds and toys. Sometimes, dogs just rub against people or objects (without mounting them), or they lick themselves.

2. Cats

Cats masturbate by licking, humping, and rubbing their genitals against objects. They may also knead, purr, or drool before masturbating.

3. Horses

A male horse, either a stallion or a gelding, willΒ use his abdominal muscles to rhythmically bounce his penis against his belly. Previously believed to be a vice caused by boredom, confinement, or discomfort, masturbation by stallions and geldings is now viewed as a normal behavior.

4. Porcupines

Female porcupines masturbate byΒ rubbing their genitals on objects like food and water dishes, sticks, and cage wire.Β They may also straddle and ride sticks.Β 

5. Birds

Male birds may be seenΒ rubbing their cloaca or vent (the underside of the tail) on a favorite toy, perch or mirror, but can also perform this behavior on the hands, arms, or shoulders of a person. Although this behavior is relatively harmless, it should be ignored or discouraged rather than accepted.

6. Squirrels

Squirrels masturbate to avoid sexually transmitted infections. It’s an act of self medication. They do it to clean their genitals and thus lower the risk of a sexually transmitted infection.

7. Bats

Bats are known to be very sexually active, and they have been known to masturbate several times a day. Bats are animals that are fairly famous for their ability to reach their genitalia with their mouths andΒ perform oral sex.

8. Penguins

Penguins, like many animals, engage in various sexual behaviors, including masturbation, although it’s not commonly discussed in scientific literature. In some species of penguins, masturbation can involve rubbing their beaks or bodies against objects, or using their flippers. This behavior is generally seen in captivity or during certain mating rituals where individuals do not have a mate immediately available.