Next airing Thu May 3, 8 p.m. ET

Koala Forest

The eucalyptus forests of eastern Australia are famous as home to cuddly-looking koalas. However, when mating season comes around it turns out they are not as cuddly as they first appear! The males make as much noise as an elephant to attract the ladies and keep rivals at bay. But it’s not exactly a romantic love song. Males are short on foreplay and will force themselves on any female they can get close to. But the strangest creatures of all are harder to spot in the forest. Unique to Australia are two types of mammals that lay eggs: platypuses and echidnas, which look like walking pincushions. The echidna’s long beak houses a whiplash tongue for scooping up termites. And the platypus lives in the forest’s rivers, routing out crayfish and other small creatures underwater. He looks harmless enough, but the male platypus has poisonous spurs on his hind legs to fend off any attackers.