For centuries, the idea of intelligent animals struck most people as ridiculous. But not any more - the latest science reveals that animals are a lot smarter than we thought. In the second of two programmes, Liz Bonnin embarks on a worldwide search for the planet's most intelligent animals.
Liz meets grey whales with emotions much like our own, unravels how the Caribbean's cleverest monkeys outwit their human neighbours, and even has a conversation with the world's cleverest chimp - with some surprising consequences.
Explore how Seattle's crows can hold grudges for years, discover that the cleverest dogs can learn over 1,000 words, and find out why Asian elephants can spend hours looking at themselves in giant mirrors.
Then there is meerkat school, eye-poking capuchin armies, and even a new version of Einstein's infamous equation written by a sheepdog. Prepare to be amazed, entertained, and even outwitted by the world's Super Smart Animals.