This is a mind-blowing video of a kestrel hovering while surveying the ground for prey, keeping its head perfectly motionless while the rest of the body makes the necessary adjustments to keep it stationary in the wind. Insane, right? Per one Youtube commenter: “It’s like a gyroscope with feathers.” Or — OR — maybe gyroscopes are like kestrels without feathers. Or maybe it’s just a bad simile. I mean it’s not like you need to hold a degree in physics or ornithology to be a Youtube commenter. All you really need is a computer and a bad attitude.