Here is a very well written thread on creating a Co2 chamber http://www.ball-pythons.net/forums/s...hlight=chamber I followed these instructions using a 10 gallon tank and 2 lbs of dry ice in a bag, with two large rabbits in the tank I opened the bag and covered the top with a piece of plywood, they slowly went to sleep and stopped breathing after about 4min. If you can't access dry ice you can create Co2 with white vinegar and baking soda, here is that page. http://www.alysion.org/euthanasia/ Co2 is very clean and they just fall asleep and don't wake up.