I worry about keeping collars on my cats when I am not home, just incase they should get themselves in a situation they can't get out of. sometimes Romeo gets in my closet, and walks along the tops on my clothes. The clothes are hanging on the pole, on hangers. cats go the craziest places. Once, Sammy got his bottom jaw stuck on his collar, probably trying to take it off. (it was a breakaway collar, that didn't breakaway!) I was home to help him at the time. now, I will only put one on them if I am taking pictures for Christmas or something, then I take them off. I am not too concerned about them sneaking out, I live on the 7th floor, and they would have to take the elevator down, if they wanted to escape!