I also use the soda bottles by cutting off the ends, slicing them end to end so I can adjust how big the opening is and sticking them INSIDE clothes dryer vent hose. I don't know about other ferrets, but mine won't play in the hoses because they collapse over time. This way they stay open and make great runways. The veasels zip, zip, zip through them! I also tape them together to make tunnels and ramps to all the cardboard boxes for playing in. Carla Roberts ADSA, AL President http://www.skunks.org/Home.htm [Posted in FML issue 3498]