The Milk snake (Lampropeltis triangulum) is a species of kingsnake. The subspecies have strikingly different appearances, and many of them have their own common names. The Milk snake is not venomous to humans.
Milk snakes have smooth and shiny scales and their typical color pattern is alternating bands of red-black-yellow or white-black-red; however, red blotches instead of bands are seen in some populations. Some Milk snakes have a striking resemblance to coral snakes, in Batesian mimicry, which likely scares away potential predators. Both Milk snakes and coral snakes possess transverse bands of red, black, and yellow. Males typically are larger than females in maturity, although females can be bulkier than males similar in length as well. Generally, more tropical populations, from Mexico and further south, reach larger adult sizes than Milk snakes living in the temperate zones.
Milk snakes are distributed from southeastern Canada through most of the continental United States to Central America, south to western Ecuador, and northern Venezuela in northern South America. They live in forested regions, tropical hardwood forests, open woodland, open prairies, grasslands, and shrublands. These snakes can also be found in small streams or marshes, and agricultural or suburban areas. In various parts across their distribution, Milk snakes often live on rocky slopes.
Milk snakes are primarily terrestrial creatures but will occasionally climb trees to prey on birds and their eggs. They are nocturnal hunters and during the day hide in old barns and under the wood. Milk snakes are generally solitary and will come together only to mate or during hibernation. During the winter they gather in groups in communal dens and go into a state of brumation. This state is very similar to hibernation, but the animal will often wake up to drink water and return to "sleep".
Milk snakes are carnivores. Young snakes typically eat slugs, insects, crickets, and earthworms. Adult diet frequently includes lizards (especially skinks), and small mammals. They are also known to eat birds and their eggs, frogs, fish, and other snakes.
Milk snakes have a polygynandrous (promiscuous) mating system in which both males and females have multiple partners in a single breeding season. They mate from early May to late June. In June and July, the female lays 3 to 24 eggs beneath logs, boards, rocks, and rotting vegetation. Once eggs are laid the female leaves. The eggs incubate for about 2 months and hatch around August or September. Hatchlings are independent at birth and are ready to fend for themselves. They will become reproductively mature at around 3 to 4 years of age.
There are no major threats to Milk snakes at present. However, in some areas, they may face significant pressure due to the pet-trade collection. Because of this species' attractiveness in the pet trade, many subspecies are now being bred in captivity for sale.
According to IUCN, the Milk snake is locally common and widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
Milk snakes play an important ecological role in their environment as they help to control populations of their prey species such as small mammals, birds, reptiles, and other snakes.