Spotted owls are formidable and stealthy predators. With their sharp eyesight and exceptional hearing, they are able to swoop down silently and under cover of darkness to grab prey with their talons. Coming in at No. 8 in our countdown, these animals are perfectly suited for living in the treetops. They prey on other arboreal species, such as squirrels and amphibians, and rather than bother to build a nest, they simply use a tree cavity or take over the abandoned nests of other birds. Like many owls, spotted owls are strictly nocturnal and are often heard but rarely seen.