We're in the middle of winter here in Ontario, but I'm thinking of bees and my spring projects...

A friend told me she has a colony of bees in a tree by her house. She likes them there. They pose no threat. I haven't seen them but am now wondering this: If they are IN a tree, they will most likely swarm in the spring from lack of space. Could I set up a box on or near the tree in hopes of catching the swarm and leave her with a populated tree??? We'd both be quite happy... and maybe I'd have a natural source for bees???