The Carlisle Mosquito Online

Friday, June 14, 2002


Biodiversity Corner Milk snake

Name: Milk snake or Lampropeltis triangulum. The common name comes from old folk lore that tells of these snakes milking cows. The folk that created this lore have evolved into editors for the National Enquirer. The genus name, Lampropeltis, means "shiny shield" which is descriptive of the very glossy appearance of a milk snake that has recently shed its skin.

When and where found: May 16, in the Towle Land by Steve Troppoli and Diane Gifford. Milk snakes frequent deciduous forests, but are also found in pine forests, meadows, sand dunes, suburban yards and around farm buildings. They have a wide geographic range and are found throughout the U.S. east of the Rockies and down through Central America into northern South America. No milk snakes were recorded in Carlisle during Massachusetts Biodiversity Days in 2000, 2001 or 2002.

Distinguishing characteristics: Milk snakes are smooth-scaled snakes that show a lot of variation in both color and markings. There are many subspecies. This one has one of the common color forms of a tan, gray, or even silvery base, and more or less evenly spaced along its back are brown blotches outlined in black. Along its sides, alternating with the large blotches, are smaller similarly colored blotches. Other variations include red, orange, yellow or white blotches with a colorful border. The milk snake has a light colored Y or V shape on the back of its neck. The Y can be clearly seen on this one. A milk snake may reach 78 inches in length. This one was estimated at 36 to 40 inches. At sexual maturity, around three years, the length is 18 to 24 inches.

Look-alikes: Milk snakes, with the coloring of this one, can be confused with copperheads, and the brighter colored ones confused with coral snakes. Since both the copperhead and the coral snake are known to be venomous, milk snakes are often in jeopardy from humans who can't tell the difference. Copperheads have large triangular heads, no markings on the head or nape, and keeled scales which give them a rough texture quite unlike the smooth slender-headed milk snake. Coral snakes are not found in New England; the northern reach of their range is around the Carolinas.

Food: Milk snakes are carnivorous and kill their prey by constriction. They prefer to feed on small mammals like chipmunks and mice but also eat birds, birds' eggs, lizards, slugs, insects and other snakes. Milk snakes themselves are prey for foxes, coyotes, raccoons, and skunks.

Behavior: In June or July, female milk snakes lay up to 20 elliptical eggs which hatch in August and September. Milk snakes seldom bask openly in the sun. They seem to prefer a partial cover of leaf litter which keeps them well disguised. When threatened, the milk snake will rapidly vibrate the tip of its tail. Steve and Diane observed this when they startled the snake with their presence. The startling was reciprocal. Milk snakes are harmless to humans and helpful in controlling rodent populations.

References: Thomas F. Tyning, Stokes Nature Guides, Guide to Amphibians and Reptiles; University of Michigan, Museum of Zoology, online at http:/

Submissions for the Biodiversity Corner are encouraged from everyone. The town is full of running, jumping and standing-still organisms. Some crave recognition; some deserve it. Help them out. Send in your ideas, your photos, your sightings, or write the whole column and send to Kay Fairweather at 392 School St, Carlisle MA 01741 or to

2002 The Carlisle Mosquito