So I have had my (male?) checkered garter for 10 yrs and I was wondering if anybody would know if it's possible for me to safely add a new garter snake to live with him, or would it be better for him to stay alone? He has lived by himself the entire time I've had him except when he was at the pet store. I heard some checkereds can be cannibals but my snake Steavy is tiny, about 18 inches and thin. Any recommendations on which species of garter to add?