Venomous snakes and spiders in Massachusetts

Massachusetts's venomous snakes are one rattlesnake species and one copperhead or cottonmouth species. Together they account for 26 licensed records; the timber rattlesnake alone has 54% of them, and the least recorded, the eastern copperhead, has 12.

One widow species (Northern black widow: 162 records) is on the Massachusetts list. There is no recluse spider on the Massachusetts list: no recluse species reaches 10 records in the state. Widow bites cause muscle pain and cramps; recluse bites can cause a slow-healing wound. Both are rare and seldom fatal.

These eight account for 95% of all licensed snake records in Massachusetts; the most recorded, the common garter snake, alone for 53%.

These eight account for 30% of all licensed spider records in Massachusetts; the most recorded, the orchard orbweaver, alone for 6%.

Observation records of snakes in Massachusetts run mostly April through October, peaking in May with 24% of them. December through February together hold under 2% of the records, so snakes in Massachusetts are rarely recorded in winter. Venomous snakes alone have six observation records with a month in Massachusetts, too few for a season of their own.

Observation records of spiders in Massachusetts run mostly April through October, peaking in August with 17% of them. December through February together hold under 2% of the records, so spiders in Massachusetts are rarely recorded in winter.

Middlesex County dominates: 26% of the state's licensed snake records come from it alone, and the top five counties hold 69%. 14 of Massachusetts's 14 counties have at least one licensed snake record.

Massachusetts counties with their own page: Barnstable County, Dukes County, Essex County, Middlesex County, Norfolk County, Plymouth County, Suffolk County and Worcester County.

Yes. Massachusetts has two venomous snake species on its list, the kind people usually call poisonous: timber rattlesnake and eastern copperhead. Strictly, snakes are venomous (they inject venom), not poisonous (harmful to eat or touch).

Yes. One species is on the Massachusetts list: the timber rattlesnake, with 14 licensed records.

Yes. One species is on the Massachusetts list: the eastern copperhead, with 12 licensed records.

Not on our list: GBIF holds 2 cottonmouth records of any license in Massachusetts (northern cottonmouth 2), fewer than 10 of any one species; such records can be genuine rarities, strays, transported animals or misidentifications. Treat any snake that looks like a copperhead or cottonmouth as venomous.

Not on our list: GBIF holds 1 coral snake record of any license in Massachusetts (eastern coral snake 1), fewer than 10 of any one species; such records can be genuine rarities, strays, transported animals or misidentifications. Treat any snake that looks like a coral snake as venomous.

Massachusetts has 14 licensed records of the timber rattlesnake, which ranks the state 26th of the 30 states where it reaches our threshold. Range in other states and photos: Timber rattlesnake profile.

Massachusetts has 12 licensed records of the eastern copperhead, which ranks the state 26th of the 27 states where it reaches our threshold. Range in other states and photos: Eastern copperhead profile.

Many snakes and spiders taken for venomous ones are harmless species with a similar look. These are the usual confusions, with each species' licensed records in Massachusetts.

Copperheads: 12 licensed records in Massachusetts. Harmless species often taken for them are also on the state list: northern water snake (347), eastern milksnake (142), eastern hog-nosed snake (12) and eastern rat snake (3). Together they have 504 licensed records, and the lookalikes are recorded 42 times as often.

Cottonmouths are not on the Massachusetts list, but they are recorded in Massachusetts two times (records of any license: northern cottonmouth 2): treat any snake like this as venomous until identified. Harmless species often taken for them in the state: northern water snake (347).

Rattlesnakes: 14 licensed records in Massachusetts. Harmless species often taken for them are also on the state list: eastern hog-nosed snake (12). It has 12 licensed records, and the two sides are recorded about equally.

Coral snakes are not on the Massachusetts list, but they are recorded in Massachusetts once (records of any license: eastern coral snake 1): treat any snake like this as venomous until identified. Harmless species often taken for them in the state: eastern milksnake (142).

Widow spiders: 162 licensed records in Massachusetts. Harmless species often taken for them are also on the state list: triangulate bud spider (72), common house spider (69), boreal combfoot (34) and twospotted cobweb spider (7). Together they have 182 licensed records, and the two sides are recorded about equally.

Recluse spiders are not on the Massachusetts list, but they are recorded in Massachusetts once (records of any license: brown recluse 1): treat any spider like this as venomous until identified. Harmless species often taken for them in the state: longbodied cellar spider (32) and spitting spider (18).

By count of venomous snake species, Massachusetts ranks 29th of 50 states, level with 7 other states. Nationally, Arizona leads with 14 species; five list none.

Of the five states bordering Massachusetts, New York lists more venomous snake species; Connecticut lists as many (Massachusetts: 2 species; New York 3, Connecticut 2, Vermont 1, New Hampshire 0, Rhode Island 0).

Venomous snakes listed next door but not in Massachusetts: the eastern massasauga (New York). The most widely shared is the timber rattlesnake, listed in three of the five bordering states.

Yes. One widow species is on the Massachusetts list: the northern black widow (162 records).

Not on our list: GBIF holds 1 brown recluse record of any license in Massachusetts (brown recluse 1), fewer than 10 of any one species; such records can be genuine rarities, strays, transported animals or misidentifications. Treat any spider that looks like a recluse as venomous.

Massachusetts has 162 licensed records of the northern black widow, which ranks the state 1st of the 30 states where it reaches our threshold. Its observation records in Massachusetts run mostly May through August, peaking in August; most licensed records come from Norfolk County, Middlesex County and Essex County. Range in other states and photos: Northern black widow profile.

No. GBIF holds no scorpion record for Massachusetts under any license. Every scorpion has venom; only the Arizona bark scorpion's sting is medically significant, and it is not on the Massachusetts list.