A couple of days ago our cat brought in a young rabbit which,...

A couple of days ago our cat brought in a young rabbit which, after chasing it round the house, I managed to catch and take it outside.
What has got us puzzled is how the hell she got it through the cat door. She can barely get herself through. She's so petrified of it falling off the hinges that she flattens herself right out to get in and out. With the rabbit gripped by the neck, it must have been a feat worthy of Houdini to get in.