In this episode, we ask: how did the blue whale become the biggest animal ever? Why do elephants have trunks? Why do ladybugs have spots? Why do some animals live so long? And, why do cats purr?

Love is in the air at Australia Zoo! Terri helps determine if Caballe the Rhino is pregnant, while Robert plays matchmaker with Coconut and Goliath, the Zoo's giant tortoises. Bindi meets newborn lemur twins, and Cleo the Python gets help shedding.

Rhino Kifaru is attempting to mate, despite his arthritic knees; tapir Jenny falls ill, and widowed porcupine Roxy meets a new mate.

In this episode, we ask: how do cats detect earthquakes? How do owls hunt in total darkness? How do cheetahs accelerate more quickly than a super car? How do sea otters keep warm in icy waters? And, how do ants heal their wounded?

It's double the trouble when Dr. Ryan and Dr. Tony tag team on a rare double knee surgery. A rescued cat melts hearts with his big hugs. And, the family gathers at their cabin for a little off-road racing in the mud.

The Game Wardens are busy on land and water. In Hunt County, residents are concerned about alleged wolves being kept as pets. Rehabilitated turtles are released on the high seas. In West Texas, wild donkeys are under threat.

What does a dog's tail wag really mean? Are cockatoos the cleverest members of the animal kingdom? Why are zebras black and white? What's the secret behind a crocodile's powerful jaws? And, how and why do chameleons change color? Find out!

Terri attends the exam of Charlie the Tiger to determine if his tumors were successfully treated. Bindi and the Small Mammal Team help develop a vaccine for Eden the Tasmanian Devil. Robert discovers the true genders of the Zoo's shingleback lizards.

A new elephant calf, Indali, is born but her young half-sister Nandita doesn't welcome the new arrival. Plus, bush dog dad Franco is under pressure as his family grows, and Apple, an onager - a very rare type of wild horse - faces a major operation.

In this episode, we ask: how do hummingbirds fly backwards? Will cockroaches really survive the apocalypse? How do dogs know when we're sad? And, is there any underwater creature more revolting than the hagfish?