A cryoprotectant is a substance that is use to protect biological tissue from freezing damage (damage due to ice formation). Arctic and Antarctic insects, fish, amphibians and reptiles create cryoprotectants in their bodies to minimize freezing damage during cold winter periods. Insects most often use sugars as cryoprotectants. Arctic frogs use glucose, but Arctic salamanders create glycerol in their livers for use as cryoprotectant.