Step 7: Additional info

Picture of Additional info
To read more on the subject of humane euthanasia of feeder animals, you can read what the American Veterinary Medical Association has published:
AVMA & humane euthanasia

or from the University of Iowa:
University of Iowa Animal Research

Guidelines for the Euthanasia of Rodent Feti and Neonates
Yale University's IACUC co2 euthanasia guidelines
University of California's euthanasia guidelines

Please note that these guidelines apply mostly to laboratory animals, as some mention the use of barbituates and other gases. But, the CO2 method is widely practiced and acceptable as a rather humane way to euthanize small animals.