Owls are famous for being able to turn their heads extremely far in either direction, but how do they do that (and, more importantly, why)?!
Reach up and touch the back of your neck can you feel the bones there?
Humans have seven bones in their neck, which help hold up the head and protect the spinal cord. Owls, in comparison, have fourteen! More bones means more flexibility, and having this allows owls to rotate their heads 270 degrees. (If 360 degrees is a way to measure a full circle, and 180 degrees is half a circle, that means owls can turn their heads more than halfway around!)
Now hold up one finger and slowly start to move it around. Keep looking at it, but don't move your head!
It's very easy for many animals, including humans, to look in different directions without moving their heads because they have special muscles in their eyes that allow them to rotate or roll. Owl eyes, on the other hand, don't have these muscles, so they cannot move their eyes without moving their whole head. If owls weren't able to turn their heads so far, they wouldn't be able to see if someone was sneaking up on them from behind (or even from the side)!