I've been hatching butterflies! I grow many different kinds of butterfly host plants and food plants so I can I can entice them into my garden. When I find butterfly eggs, I collect a few, hatch them out and feed them until they go into chrysilis. Usually, after about two weeks or so, they hatch and I let them go back into my garden. I sometimes also provide teachers and parents a few so they can enjoy the wonder of a butterfly!
Last fall, we had so many late caterpillars that I began to worry they would freeze. I collected as many as I could and put them into my container. They went into chrysilis but didn't hatch before winter set in. I had always read that some would overwinter and not migrate but I had never had any do it.