They will graduate to larger, haired mice as they grow. These are flighty little wigglers but once in hand they settle down a good bit. Mine seem to prefer musking over biting but I don't like to mess with them much either way. These are one of those species that are just a joy to observe cruising around their enclosures, doing their thing - active little boogers that they are.
I believe you're thinking of the San Francisco Garter, T.s. tetrataenia, which is endangered.