What Do Garter Snakes Eat?
North American Garter Snakes will eat live fish of a suitable size. Types of live fish which are suitable to feed to Garter Snakes are guppies, platties, tilapia and mosquito fish. Avoid gold fish as they contain an enzyme which destroys vitamin B1 and feeding a diet of only goldfish will result in vitamin B1 deficiencies. Vitamin B1 deficiencies present with neurological symptoms and can be fatal. Live fish also carry internal parasites and Garter Snakes which are fed live fish should be de wormed once a year. Feed live fish to your Garter Snakes by putting them in your Garter Snakes water bowl.
Live fish are expensive and it is easier and cheaper to feed frozen fish to your Garter Snakes. Freezing also kills internal parasites. The best frozen fish to feed to your Garter Snakes are frozen lance fish. Frozen lance fish are small whole fish which can be purchased from the aquarium section of most pet shops. Frozen lance fish contain the internal organs and bones and are much more nutritious than fish fillets. Frozen lance fish are also free of the enzyme which destroys vitamin B1 and unlike white bait are safe to feed to your Garter Snake. Defrost the frozen lance fish as needed and feed them to your Garter Snakes using feeding tongs or by leaving the fish in the cage.
Garter Snakes feed heavily on frogs in the wild. However frogs do not make a good food for captive Garter Snakes for several reasons. Frogs are very difficult to acquire and usually have to be collected from the wild. Wild frogs are often heavily infested with parasites and many frogs have toxic skin secretions which could harm your Garter Snake. Avoid feeding frogs to your Garter Snakes, rather feed your pet Garter Snake the other food items on this list.
Garter Snakes love earthworms, especially when they are babies and will rarely refuse to eat them. Garter Snakes that are fed earthworms need to be fed much more often than Garter Snakes which are eating fish or mice. If you are feeding your Garter Snake earthworms you will need to feed them every second day as opposed to 2-3 times a week when feeding fish or once a week when feeding mice. Do not feed your Garter Snakes red wriggler earthworms as these are toxic to Garter Snakes. Red wrigglers are the earthworms used to make compost and are also sold as fishing bait. Earthworms harvested from a pesticide free garden are safe to use as Garter Snake food.
Garter Snakes will sometimes eat mice in captivity. Some species such as Checkered Garter Snakes will readily accept mice while some species such as Red Sided Garter Snakes are less willing to eat mice. I have found that adult and sub adult Garter Snakes accept mice more readily than younger Garter Snakes. I have also found that female Garter Snakes accept mice more readily than males, this could be because female Garter Snakes are bigger than males and can take bigger food items. You can get your pet Garter Snake to eat mice by rubbing some fish on a pre killed mouse making the mouse smell like a fish. I have found that Garter Snakes which are fed mice can become obese fairly quickly so I do not feed mice exclusively but rather provide a varied diet of fish, earthworms and the occasional mouse or rat pup.