WC Garter Snake - care tips?

A couple of days ago my brother gave me an eastern garter snake that came in his load of mulch (he's a landscaper). He was unable to run the little creature off, so he put it in a bucket and brought it to me (the snake-loving kid sister). I haven't decided to permanently keep it, but I do want to for a while. I'm looking for recommendations on feeding frequency and amounts, in particular. I know they'll eat earthworms, salamanders, frogs, tadpoles and minnows. It ate a couple of worms last night and I purchased a couple of feeder goldfish to try out. How often should I offer prey and how much prey should I offer at one time? Any input is appreciated!

Thanks,
Dianne

just feed it about twice a week and make sure it doesnt loose leight. if you do keep it i would take it to you vet to check it for paircites.
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