Hi I made a gas chamber and i killed off 13 weaned rats nicely. Here is the link http://www.alysion.org/euthanasia/index.html . I am so excited because i thought i would do something wrong but by the time i poured out 1 cup vinegar in the bag about 1/3 to 1/2 of them were already dead or atleast seemed like it but all of them were dead in a mear 10-15 minutes more like 10 though.I wish I would have taken pics but now i have a nice bundle of rats in the freezer!