If the snake feels insecure, he will not eat, even if he is very hungry. Do not handle the snake after it eats. You must wait until it has digested its meal otherwise it may regurgitate the meal and refuse to eat for several days following. For brown snakes or garter snakes, earthworms are a good choice of food item. Worms are easy to collect after dark on a dewy or rainy night or can be purchased at a bait store.
Many snakes eat fish, fresh or frozen, which can also be purchased.
Frozen fish should only be used when fresh fish is not available. There has been much evidence suggesting that a natural diet is the best for a snake in captivity. Snakes need to eat at regular intervals. Ones that are smaller than three feet should be fed prey the size of a mouse once or twice a week. Larger snakes take larger prey at less frequent intervals.