Koalas may seem like lazy mammals, spending between 18 and 22 hours a day asleep. When it comes to mating, though, these lethargic animals can be pretty active. Found throughout the Eucalypt Woodlands of Australia, koalas are quite solitary animals. Each koala sets up a home base, which can span up to hundreds of acres so that each individual has enough space to never run into another koala. If two territorial males encounter one another, things can get bad.

Koala, Unknownlist, Double Organs

During the mating season, which occurs in the spring and summer, interactions between the males and females increase. When koalas mate, the pair quickly gets to business. “It’s not particularly a gentle process,” said Ellis from Live Science.

Koala, Unknownlist, Koala Mating,

The male climbs onto the female from behind, bites the back of her neck, and briefly copulates with her. Like kangaroos and other mammals, male koalas have a double-headed penis and females have two vaginas. After mating, the female returns to her home range to prepare for her offspring. She won’t begin mating again until her newborn is fully grown about one year later. The male, on the other hand, may go on to mate once or twice more that season.