False — Birds

The story behind the answer

False. Birds are defined by traits you can’t miss: feathers and a beak. Every bird—flying or flightless—has feathers, two legs, and forelimbs modified as wings. If an animal lacks feathers or a beak, it isn’t a bird, no matter how much it resembles one or even if it can fly.

Helpful context: birds are the only living dinosaurs, and feathers are unique to them today. Don’t be fooled by “wings”: bats are mammals with skin-stretched wings and visible fingers; insects have six legs and exoskeletons; aircraft are machines. Penguins and ostriches can’t fly, yet they’re unquestionably birds because they have feathers and beaks and lay eggs. Memory tip: feathers-first rule—no feathers, not a bird.