Donna- The end of the penis of a male ferret has a little bone in it that is hook-shaped. Sometimes it gets stuck on the end of a cage - I've had this happen with my own ferrets, although it seems to happen more often in whole males rather than neutered. Go to a book store or school supply store and look for those clear, plastic book covers that have a separate piece of plastic that you fasten on to the right side of the plastic covers so it keeps your paper nice and neat. These pieces come in assorted colors - black, gray, etc - and fasten the plastic book cover together by sliding it down over the 2 clear plastic pieces (do you understand what I'm talking about?). I buy the set - which is like 69 cents, and throw away the clear plastic covering, and I keep the fastening piece. This same fastening piece will fit nicely over the edges of your cage door openings so as they go in and out, they will slide over a smooth surface and avoid getting stuck. Hope this helps. Debbie Riccio WNYFLFA Rochester, NY [Posted in FML issue 1271]