Welcome! The proper name is "garter" many people call them garder or garden snakes lol. the scientific name for your checkereds are "Thamnophis marcianus". I would like to see photos of them if you are able to post cause we have been having trouble with that feature lately. As Steve said, feel free to ask questions. There are many experienced keepers/breeders on this forum. Are you feeding them just guppies? If not, what other food items are you offering? The care sheet Steve linked has a list of safe fish and other food options.