The state is home to only two species of venomous snakes, both of which are pit vipers. Encounters are extremely rare and highly localized, meaning most residents will never encounter one, especially in densely populated areas. Awareness and proper identification are necessary for anyone spending time in the state’s natural areas.
The Two Venomous Species of Massachusetts
The two venomous species native to the state are the Timber Rattlesnake (Crotalus horridus) and the Northern Copperhead (Agkistrodon contortrix). Both are pit vipers, characterized by a heat-sensing pit located between the eye and the nostril. The Timber Rattlesnake is considered the more dangerous, but it is also the more rare and localized species. The Northern Copperhead is uncommon, though its distribution is slightly less restricted. Both snakes are protected under state law due to low numbers and threats from habitat loss.
Visual Identification and Temperament
Identifying these two species relies on observing distinct physical features, particularly the head shape and body pattern. The Timber Rattlesnake is a large, heavy-bodied snake with a broad, triangular head and a dark, solid-black tail ending in a characteristic rattle. Its coloring is variable, ranging from yellowish to dark gray or black, typically featuring dark, V-shaped crossbands along the back. The Copperhead is known for its reddish-brown or copper coloration, featuring striking, dark brown, hourglass-shaped crossbands against a lighter background.
Both species share the distinct, triangular head shape and vertically elliptical pupils common among pit vipers. Despite their venom, both the Timber Rattlesnake and the Copperhead are mild-mannered and non-aggressive toward people. They are secretive and prefer to remain still or slowly retreat when approached, relying on camouflage to avoid detection. Bites usually occur only if the snake is accidentally stepped on or actively handled, so it is important to leave them undisturbed.
Geographic Range and Protection Status
The Timber Rattlesnake population is severely fragmented, existing almost exclusively in the western counties, favoring remote, mountainous, and rocky woodlands. The Northern Copperhead is found in small, highly isolated populations primarily limited to specific areas in Norfolk and Hampden Counties and parts of the Connecticut River Valley. The isolation of these populations makes them vulnerable to environmental and genetic threats.
Both species are listed as endangered under the Massachusetts Endangered Species Act (MESA). This protection status makes it illegal to harass, kill, collect, or possess either species without a special permit. The state mandates this stringent protection because these snakes are vital members of the ecosystem. Killing an endangered snake can result in substantial fines and restitution payments.
Encounter Safety and Prevention
Minimizing the risk of an encounter requires being mindful of snake habitats and taking simple precautions when exploring natural areas. When hiking, wear sturdy, closed-toe footwear and long pants, which offer a physical barrier against a potential strike. Never reach into rocky crevices, under logs, or into thick brush without first checking the area visually, as these are common hiding spots. Hikers should remain on established trails and watch where they place their hands and feet, particularly when stepping over obstacles.
If a venomous snake is encountered, remain calm and slowly back away, giving the animal a wide berth. Do not attempt to capture, harm, or move the snake, even if it is near a residence, as this is when most bites occur. If a bite occurs, seek immediate medical attention by calling emergency services. Keep the victim calm and hold the affected limb below the level of the heart to slow the spread of venom. Avoid unproven home remedies such as cutting the wound, applying a tourniquet, or attempting to suck out the venom, as these actions can cause more harm.