Dolphins call one another by name, ducklings can pass complicated tests in abstract thinking, and snails like to spin on hamster exercise wheels. As biologist Karsten Brensing points out in this eye-opening study, animals aren't so different from us. In fact, they can resemble us in ways that aren't altogether admirable: bonobos delight in dirty talk, ants recognize themselves in mirrors and spruce themselves up before they return home, and dogs punish disloyalty—though they are also capable of forgiveness if you apologize to them.