First off - the large ball with one hole is NOT made by the same people who make the ball with six holes. The first ball is really large and, yes Rudy, there are at least three documented deaths via this ball. Kits and older ferrets without the strength to push to ball off the hole if/when it lays to rest on the opening will overheat and suffucate. the easiest method to remedy the hazard is to drill holes in the opposite end so air will alway flow through. I have one of these balls and have had no problems, but i did talke the drill to it. the ball with six openings is made by Super Pets and was designed before the creation of Ferret Funnels, but now is part of the tunnel proccess. some older balls are one piece, while the newer model comes in two pieces and fits together (if memory serves me). My ferrets still like the pretzel barrel best, and it is clear so I can see the action. Pam [Posted in FML issue 1400]