"They don't eat insects"

Not true. The insect eating has been proven in wandering garters. Wild wanderings found on road dead, have been found with their guts full of grasshoppers, consistently! Same goes for baby gopher snakes and this is in colorado too. Not saying it's good for them due to indigestible exoskeletons, but crickets are much softer. I don't recommend feeding them insects, I'm just saying that the fact is, many wild wandering garters eat them. I imagine this is in very late summer when it's hot and dry and other food is scarce.