Mine sleep with it on if they sleep on the bed, off if they sleep in their crates. They always have them off if they're crated or if I'm not around to keep an eye on them. Tyr's usual collar is a fursaver, which is like a choke, but any time he's loose with me and wearing his collar, outside of training, I switch him to either a flat collar or a prong collar. I have witnessed prong collars breaking apart and coming off if they get caught on something, so I don't worry about that too much.