- The bold red, black, and white bands of color common to milk snakes and some other species of kingsnakes, evolved in mimicry of the venomous coral snake. Coral snakes, which are red, black and yellow are found in the extreme south eastern part of the US, along the gulf coast. A handy poem can help you tell them from king snakes: Red on yellow, kill a fellow. Red on black, friendly jack. Meaning if the red band touches yellow, it is a venomous coral snake and if the red touches black, it is a kingsnake or milk snake. This only works in the US. In South or Central America, all bets are off and you should avoid any snake (or other animal) with bright colors because it's very hard to tell harmless mimics from their more dangerous models.