Funny related story:
I had a cat when i was a university student. He liked that bite your hand when you sleep thing. Full commando style, he would go under the bed and do sudden attacks, then retreat to the middle of the bed where he was unreachable. Long story short we started sleeping with doors closed ( was living with my brother ). One of my brother's doors was a rolling one though, which wouldn't lock. But it seemed too heavy for a few months old kitten to open. The little bastard figured it out. He would lie parallel to the door, but both of his front legs in the few milimeters opening ( his claws actually ), pull with all he got until he created a couple of centimeters opening, then stand up go stick his face in there and widen it moving his head, then the same with his body, boom, he was in. And he was doing it mechanically, routine style, like "i got this, 3 steps to open it, 1,2,3, done"
Dreyth this one has an awesome face.