For instance, did you know that chickens used to fly as easily as eagles? Then a whole generation were bred from a rooster with acrophobia and they've been ground-hugging fraidy ca... moreFor instance, did you know that chickens used to fly as easily as eagles? Then a whole generation were bred from a rooster with acrophobia and they've been ground-hugging fraidy cats (well, technically I suppose that's fraidy birds) ever since.