Took the grand daughter to fish southern Ill Dam.Stoped to get nightcrawlers and the guy ask what color did I want.He had these green ones.They were fat and lively.Cut them in half and hammered the fish.First time for Jess and she loved it.Asked the guy on the way out of town what he used.It's called "worm glow".Put a table spoon in with regular crawlers in the container they come in and they turn green,fat and lively.