The Sinaloan milk snake is not venomous, but its bright colors act as a false advertisement to potential predators. Many milk snake subspecies, including the Sinaloan milk snake, exhibit aposematic mimicry—their color patterns resemble those of the venomous copperhead or coral snake.
The common name, milk snake, originated from a belief that these snakes milked cows. This myth probably began when farmers sought some excuse for why a cow was producing less milk than usual. The snakes, drawn to the mice in the barn, were convenient culprits. Needless to say, milk is not a component of any snake's diet—all snakes are carnivorous.
Milk snakes are a solitary species rarely seen in the open during the day, but they can often be spotted crossing roads at night. They typically stay hidden under rotting logs or damp trash. The only time these snakes are found in groups is during hibernation. Just before and after hibernation, they can be seen together basking in the sun.
When threatened, this snake vibrates its tail creating a sound reminiscent of a rattlesnake. It also discharges a pungent fluid from its cloaca as a warning. These behaviors may deter some predators.
