Welcome to the best garter snake forum in the world! Many of the members on here have a lot of experience and we would love to answer any questions you have! Feeding problems often occur when the garter is stressed, too hot, too cold, or just plain scared. If possible, try to contact the people you bought him from and ask what they fed him. Also, try to stay away from thiaminase containing fish. The 2 most commonly sold are goldfish and rosy-red minnows. If he is still a baby, try putting him in a little sauce cup (see picture below) with a tiny bit of water (about 1/3 the height of him) and put a feeder guppy in there. This works with 90% of the picky eaters that I have.

This is the type of sauce cup I was talking about.
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