The biologist Liz Bonnin explores why some of the most bizarre and surprising animals pair up with each other, and with us. She'll scour the globe in search of the most extraordinary and cute animal relationships to investigate why such odd couples sometimes pair up. Everything from dogs mothering baby tigers and polar bears befriending huskies; to buffalos bonding with grown men and lions behaving like our brothers. We're utterly captivated by animals that behave in ways that we think of as uniquely human. Millions of us watch clips of animals showing friendship, genuine affection and maybe even love towards totally different species that would never normally come together. But these are not just freak occurrences; there is real science to explain these bonds... Liz will discover how oxytocin, the love hormone, plays a vital part in bringing the oddest animals together. There's the donkey and the chicken that love spending time with each other so much so that they become ill if separated. And the biological need to mother can shake up the natural order with leopards mothering baby baboons and deer adopting dogs as their own young. Science can also explain why some of the most dangerous animals can seek out humans for companionship. When animals imprint on us from a very young age the most unusual friendships form - Jessica the Hippo is now part of a human family! And these remarkable relationships don't just happen in captivity - they happen in the wild too. From the dolphins that help the Brazilian fishermen with their catch, to the Honey Guide Birds in Kenya that lead the Boran tribesmen to bee hives. Across the series Liz will discover that it is these human-like qualities, found in the most surprising of animals, which will change the way we see the animal kingdom.