We've just inherited an 18 month old red sided garter snake and my partner decided it would be a good idea to put a little aquarium in his terrarium. it's only got a redcrab some snails and a few tadpoles in but it did have a molly. Now i know garters do eat fish but i would of put money on this one being too big for him but it's gone missing and cant find it anywhere. Will it cause him any problems if it was too big? or any other problems related to him eating out of the aquarium?