Connecticut has 2 venomous snakes named by official sources: Northern Copperhead and Timber Rattlesnake. Each one is labelled venomous by Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division.
The 2 venomous snakes of Connecticut
Recognize them from a distance; a photo cannot confirm that a snake is safe. Identifying animals safely.
Venom: “The copperhead is one of two venomous snake species found in Connecticut; the other is the state-endangered timber rattlesnake.” (Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division)
Range: Populations are spread out in Connecticut, but the greatest abundance of copperheads is found in the Central Connecticut Lowland (trap rock) ridges. These ridges are located on the western side of the Connecticut River in Hartford, Middlesex, and New Haven Counties.
Habitat: They are predominantly found along wooded, basalt ridges, talus slopes, and rocky hillsides, or at the edges of meadows. (Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division)
Venom: “The timber rattlesnake is one of only two venomous species found in Connecticut; the other is the northern copperhead.” (Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division)
Habitat: In Connecticut, timber rattlesnakes inhabit deciduous forests (often second growth) in rugged terrain with steep ledges, rock slides, and a nearby water supply. (Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division)
Copperheads have bold hourglass-shaped bands, and young copperheads under about 12 inches have bright yellow tail tips. Brown snakes have small spots, not hourglass bands.
Brown Snake (Dekay's Brownsnake) or Red-bellied Snake?
The copperhead's head is coppery with no marks; the milksnake's head is light with brownish marks (Pennsylvania). Tennessee: copperhead has a copper-colored, unmarked head and triangular shapes on the side of the body. Pennsylvania says the eastern milksnake is the snake most often killed by mistake for a copperhead. Belly colour is not used here: Pennsylvania's own pages describe the copperhead belly two different ways (uniform cream in one account, mottled white to gray in another).
Black Racer or Timber rattlesnake?
Photo: Everglades NPS from Homestead, Florida, United States · Public domain · Wikimedia Commons
Call 911 or Poison Help at 1-800-222-1222 right away. Poison Help connects you to your local poison center, any time of day.
Official advice from Connecticut Department of Environmental Protection (now DEEP), Bureau of Natural Resources, Wildlife Division and Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division:
Bear-related emergencies: DEEP 24-hour Dispatch Center 860-424-3333. Wildlife sightings (bear, bobcat, moose, fisher, bats, endangered species and others) via the DEEP Report a Wildlife Sighting page; DEEP Wildlife Division 860-424-3011. Spotted lanternfly: CAES SLF Reporting Form. Timber rattlesnake violations: TIP hotline 800-842-HELP. Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division
Venom labels come only from official sources and link to them; "Not stated" never means harmless. How labels work.
Sources
Report a Wildlife Sighting. Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated September 22, 2026; checked November 3, 2026.Quoted passages (1)
“For bear-related emergencies, please call DEEP's 24-hour Dispatch Center at 860-424-3333.”
Snakes of Connecticut. Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated July 2026; checked November 3, 2026.Quoted passages (1)
“The answer is 14! Only 2 of the 14 native snake species are venomous -- the northern copperhead and timber rattlesnake.”
Common Gartersnake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (2)
“Gartersnakes are harmless to people and are NOT venomous.”
“The saliva of the common gartersnake appears to be toxic to amphibians and other small animals and a bite may produce swelling or a rash in some people.”
Common Ribbonsnake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (1)
“The common ribbonsnake is non-venomous and harmless to humans.”
Dekay's Brownsnake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated August 15, 2022; checked November 3, 2026.Quoted passages (1)
“This harmless snake is non-venomous and does not bite.”
Eastern Hog-nosed Snake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (1)
“This completely harmless, non-venomous snake can put on an act that often frightens or alarms those who encounter it.”
Eastern Milksnake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (1)
“Understanding that the milksnake is non-venomous is important.”
Eastern Ratsnake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (1)
“Eastern ratsnakes are harmless to people and are NOT venomous.”
Northern Redbelly Snake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (2)
“The northern redbelly snake is sometimes confused with the northern brownsnake, northern ring-necked snake, and eastern wormsnake. All are nonvenomous species.”
“Northern redbelly snakes are typically active in May through October.”
Eastern Wormsnake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (1)
“Eastern wormsnakes are active from May through September.”
Northern Black Racer (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (1)
“Understanding that the black racer is non-venomous is important.”
Northern Copperhead (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (5)
“The copperhead is one of two venomous snake species found in Connecticut; the other is the state-endangered timber rattlesnake.”
“If provoked or handled, a copperhead may strike and bite. The bite, while painful and capable of producing severe illness, rarely results in the death of a human. However, seek medical attention immediately if bitten.”
“However, seek medical attention immediately if bitten.”
“Copperheads are active from April through October, spending the rest of the year in dens.”
“Copperheads are mostly absent from the northeastern and northwestern portions of the state and less common east of the Connecticut River”
Smooth Greensnake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (1)
“Smooth greensnakes are nonvenomous and completely harmless to humans.”
Timber Rattlesnake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated March 8, 2018; checked November 3, 2026.Quoted passages (4)
“The timber rattlesnake is one of only two venomous species found in Connecticut; the other is the northern copperhead.”
“Do NOT attempt to kill any rattlesnakes under any circumstances as this is an illegal action.”
“Connecticut’s rattlesnakes are active mid-April through October.”
“Once documented in over 20 towns in Connecticut, this snake is now limited to isolated populations in about 10 towns in the central and western portions of the state.”
“These venomous snakes, along with the other 12 Connecticut snake species, are not aggressive and will only bite if threatened or handled. If left alone, snakes pose no threat to people.”
“If you suspect a snake in your yard is venomous, observe it from a safe distance and call the Wildlife Division for advice.”
Northern Ring-necked Snake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (1)
“Ring-necked snakes are active from May through mid-October.”
Northern Watersnake (Wildlife Fact Sheet). Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated on; checked November 3, 2026.Quoted passages (1)
“Although these two species may be similar in appearance, water moccasins do not occur in Connecticut.”
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