thats awful. i dont thing your rediculous, i'm a cat lover and i have pet rats.
unfortunately, it is not illegal to feed mice live to snakes. i wish it were, but it's not.
petco is awful the way they can't even tell the genders of the animals they sell.
in the future, you could have the males fixed, maybe. also, male mice cannot live in the same cage, they often fight to the death.
just a random fact, i know petco has 2 kinds of mice: fancy, and feeder, or "common". in reality, all those mice are from the same breeders, often from the same litter. there is no difference between them whatsoever, except their color. but petco labels them like that so most people are under the impression that the feeders are geneticaly different. its awful.