Discover Maryland's Herps

Field Guide to Maryland's Snakes (Order Squamata)

Sub-order Serpentes, Family Colubridae

Eastern Ratsnake
Pantherophis alleghaniensis

Photo of Adult Eastern Ratsnake courtesy of John White
Photo of Adult Eastern Ratsnake courtesy of John White


42 - 72 inches. Record - 101 inches.

Illustration of post ocular stripe on Eastern Rat SnakeAppearance

  • Our largest snake.
  • A plain shiny black back with weakly keeled scales.
  • The belly has an irregular black and white checkerboard pattern, particularly towards the head.
  • The chin and throat are cream or white.
  • Young have strongly patterned backs of gray and brown blotches on pale grey.
  • Young are often mistakenly identified as Northern Pinesnakes
    (Pituophis melanoleucus melanoleucus).
  • Photo of Juvenile Eastern Ratsnake courtesy of Scott A. Smith
    Photo of Juvenile Eastern Ratsnake courtesy of Scott A. Smith


    Occur in a variety of habitats including farmlands, hardwood forests, forested wetlands, isolated urban woodlots and backyards. They do especially well in edge habitats. An arboreal species they are notorious for getting into human residences, where they may live in attics undetected.

    How to Find

    Look around farms, abandoned buildings and any edge areas. Drive slowly on country roads just after sunset and look for snakes crossing roadways. Non-venomous, but readily give a painful bite when handled. This is the most commonly reported snake by landowners in Maryland. Take a close look as it is probably what you are seeing in your yard.

    Distribution in Maryland

    One of our most common snakes, it is found statewide.


    Maryland Distribution Map for Eastern Rat Snake

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    Maryland Amphibian
    and Reptile Atlas Project

    "A Joint Project of the Natural History Society of Maryland, Inc. and the Maryland Department of Natural Resources"

    For monthly newsletters of the Maryland Amphibian & Reptile Atlas Project click on Recent Newsletters and scroll down to the MARA Newsletters.

    The Maryland Herpetology Field Guide is a cooperative effort of the MD Natural Heritage Program and the MD Biological Stream Survey within the Department of Natural Resources and their partners. We wish to thank all who contributed field records, text, and photographs, as well as support throughout its development.