Update!
Chipper removed the bell from the rope a while ago, and now mates with the bell and carries it around everywhere. I just came downstairs from nap time, and he had destroyed a toy and has the bell in the pile of shredded wood and is covering it with his wings and body. Seems very nesty and eggy to me and I'm not sure it's good. I've already called his vet for advice since we were just discussing his hormonal behavior the other day. Do you think I should remove the bell? Maybe he needs to be going into a dark room/sleeping cage earlier instead of the cage cover?