While other owls spend their days sleeping off the night before, the northern hawk-owl is a bird of a different feather. One of the few owls active during the day, that piercing gaze scours the boreal forests of North America, Europe, and Asia for prey. Northern hawk-owls aren't picky eaters: Mice, rats, voles, lemmings, rabbits, shrews, moles, and the occasional frog are all on the menu. These vocal birds have different calls for mating, chatting with their young, and warning that danger is nearby. If you get too close to their nest, protective parents have been known to swoop at humans to keep them away.