Venomous snakes and spiders in Missouri
Missouri has five venomous snake species among the 36 snake species listed there: northern cottonmouth, eastern copperhead, timber rattlesnake, pygmy rattlesnake and western massasauga. The eastern massasauga is recorded there too, but only four times (records of any license), too few to list. The northern cottonmouth accounts for the most records (70), and venomous species make up 10% of all 1,883 licensed snake records in the state. On the spider side, three species are medically significant: brown recluse, northern black widow and southern black widow.
Venomous snakes of Missouri
Missouri's venomous snakes are three rattlesnake species and two copperhead or cottonmouth species. Together they account for 186 licensed records; the northern cottonmouth alone has 38% of them, and the least recorded, the western massasauga, has 11.
Also recorded in Missouri under any license, but fewer than 10 times and so not counted above: the eastern massasauga (4). Such records can be genuine rarities, strays or old misidentifications; see the rare list.
Dangerous spiders of Missouri
Two widow species (Northern black widow: 31 records, Southern black widow: 7 records) and one recluse species (Brown recluse: 174 records) are on the Missouri list. Widow bites cause muscle pain and cramps; recluse bites can cause a slow-healing wound. Both are rare and seldom fatal.
Are there scorpions in Missouri?
Yes. One scorpion species is recorded in Missouri, from 50 licensed records: Striped bark scorpion (50 records). Every scorpion has venom; only the Arizona bark scorpion's sting is medically significant, and it is not on the Missouri list.
Other snakes recorded most in Missouri
These eight account for 60% of all licensed snake records in Missouri; the most recorded, the ring-necked snake, alone for 13%.
Other spiders recorded most in Missouri
These eight account for 31% of all licensed spider records in Missouri; the most recorded, the bold jumper, alone for 7%.
When venomous snakes are out in Missouri
Observation records of venomous snakes in Missouri run mostly April through October, peaking in October with 38% of them. December through February together hold under 2% of the records, so venomous snakes in Missouri are rarely recorded in winter.
Season of each venomous snake
| Species | Main season | Peak month | Winter share | Observation records |
|---|---|---|---|---|
| Northern cottonmouth | April through October | October | 0% | 61 |
| Eastern copperhead | April through September | September | 0% | 45 |
When spiders are most active in Missouri
Observation records of spiders in Missouri 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 Missouri are rarely recorded in winter.
When scorpions are out in Missouri
Observation records of scorpions in Missouri run mostly April through October, peaking in May with 43% of them. Winter (December to February) holds 5% of the records.
Counties with the most venomous snake records
Cape Girardeau County has the most records of venomous snakes in Missouri, 41, most of them of the northern cottonmouth. Jefferson County and Shannon County follow.
| # | County | Records | Most recorded there |
|---|---|---|---|
| 1 | Cape Girardeau County | 41 | Northern cottonmouth |
| 2 | Jefferson County | 8 | Eastern copperhead |
| 3 | Shannon County | 7 | Northern cottonmouth |
| 4 | Perry County | 7 | Northern cottonmouth |
| 5 | Wayne County | 5 | Eastern copperhead |
| 6 | Miller County | 5 | Northern cottonmouth |
| 7 | Phelps County | 5 | Eastern copperhead |
| 8 | Butler County | 4 | Eastern copperhead |
| 9 | Boone County | 4 | Eastern copperhead |
| 10 | Franklin County | 4 | Eastern copperhead |
Where in Missouri are snakes recorded most?
Holt County leads with 206 records (11%), followed by St. Louis County and Jefferson County; the top five counties hold 35% of the total. 96 of Missouri's 114 counties have at least one licensed snake record.
| # | County | Records | Share |
|---|---|---|---|
| 1 | Holt County | 206 | 10.9% |
| 2 | St. Louis County | 167 | 8.9% |
| 3 | Jefferson County | 135 | 7.2% |
| 4 | Cape Girardeau County | 85 | 4.5% |
| 5 | Texas County | 61 | 3.2% |
| 6 | Boone County | 53 | 2.8% |
| 7 | Franklin County | 52 | 2.8% |
| 8 | Jackson County | 50 | 2.7% |
| 9 | Phelps County | 48 | 2.5% |
| 10 | Pike County | 45 | 2.4% |
| 11 | Dent County | 43 | 2.3% |
| 12 | Lincoln County | 41 | 2.2% |
Missouri county with its own page: St. Louis County.
Are there poisonous snakes in Missouri?
Yes. Missouri has five venomous snake species on its list, the kind people usually call poisonous: northern cottonmouth, eastern copperhead, timber rattlesnake, pygmy rattlesnake and western massasauga. The eastern massasauga is recorded there too, but only four times (records of any license), too few to list. Strictly, snakes are venomous (they inject venom), not poisonous (harmful to eat or touch).
Are there rattlesnakes in Missouri?
Yes. Three species are on the Missouri list: the timber rattlesnake, the pygmy rattlesnake and the western massasauga, with 51 licensed records between them. The eastern massasauga is recorded there too, but only four times (records of any license), too few to list.
Are there copperheads in Missouri?
Yes. One species is on the Missouri list: the eastern copperhead, with 65 licensed records. Most licensed records of the eastern copperhead come from Jefferson County, Boone County and Wayne County.
Are there cottonmouths (water moccasins) in Missouri?
Yes. One species is on the Missouri list: the northern cottonmouth, with 70 licensed records. Most licensed records of the northern cottonmouth come from Cape Girardeau County, Perry County and Miller County.
Are there coral snakes in Missouri?
No. GBIF holds no coral snake record for Missouri under any license.
Northern cottonmouth (Agkistrodon piscivorus)
Missouri has 70 licensed records of the northern cottonmouth, which ranks the state 14th of the 16 states where it reaches our threshold. Its observation records in Missouri run mostly April through October, peaking in October; most licensed records come from Cape Girardeau County, Perry County and Miller County. Range in other states and photos: Northern cottonmouth profile.
Eastern copperhead (Agkistrodon contortrix)
Missouri has 65 licensed records of the eastern copperhead, which ranks the state 18th of the 27 states where it reaches our threshold. Its observation records in Missouri run mostly April through September, peaking in September; most licensed records come from Jefferson County, Boone County and Wayne County. Range in other states and photos: Eastern copperhead profile.
Timber rattlesnake (Crotalus horridus)
Missouri has 29 licensed records of the timber rattlesnake, which ranks the state 22nd of the 30 states where it reaches our threshold. Range in other states and photos: Timber rattlesnake profile.
Pygmy rattlesnake (Sistrurus miliarius)
Missouri has 11 licensed records of the pygmy rattlesnake, which ranks the state 10th of the 11 states where it reaches our threshold. Range in other states and photos: Pygmy rattlesnake profile.
Western massasauga (Sistrurus tergeminus)
Missouri has 11 licensed records of the western massasauga, which ranks the state 8th of the 8 states where it reaches our threshold. Range in other states and photos: Western massasauga profile.
Harmless lookalikes in Missouri
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 Missouri.
What looks like a copperhead in Missouri
Copperheads: 65 licensed records in Missouri. Harmless species often taken for them are also on the state list: northern water snake (202), plain-bellied watersnake (41), eastern milksnake (25), eastern hog-nosed snake (16) and eastern rat snake (1). Together they have 285 licensed records, and the lookalikes are recorded 4 times as often.
What looks like a cottonmouth in Missouri
Cottonmouths: 70 licensed records in Missouri. Harmless species often taken for them are also on the state list: northern water snake (202), diamondback water snake (57), plain-bellied watersnake (41), southern watersnake (12) and green water snake (10). Together they have 324 licensed records, and the lookalikes are recorded 5 times as often.
What looks like a rattlesnake in Missouri
Rattlesnakes: 51 licensed records in Missouri. Harmless species often taken for them are also on the state list: eastern hog-nosed snake (16), western foxsnake (4), Great Plains rat snake (3) and gopher snake (1). Together they have 24 licensed records, and here the venomous species are the more recorded side, 2.1 to 1.
What looks like a coral snake in Missouri
No coral snakes reach the Missouri list, and GBIF holds no coral snake record for Missouri under any license, so a snake taken for one here is most likely a harmless lookalike. Those recorded in the state: eastern milksnake (25).
What looks like a widow spider in Missouri
Widow spiders: 38 licensed records in Missouri. Harmless species often taken for them are also on the state list: triangulate bud spider (25), common house spider (11) and boreal combfoot (1). Together they have 37 licensed records, and the two sides are recorded about equally.
What looks like a recluse spider in Missouri
Recluse spiders: 174 licensed records in Missouri. Harmless species often taken for them are also on the state list: longbodied cellar spider (9) and spitting spider (1). Together they have 10 licensed records, and here the venomous species are the more recorded side, 17.4 to 1.
How Missouri compares
By count of venomous snake species, Missouri ranks 12th of 50 states, level with 5 other states. Nationally, Arizona leads with 14 species; five list none.
Of the eight states bordering Missouri, Oklahoma and Kansas list more venomous snake species; Arkansas lists as many (Missouri: 5 species; Oklahoma 8, Kansas 6, Arkansas 5, Illinois 4, Nebraska 4, Iowa 3, Kentucky 3, Tennessee 3).
Venomous snakes listed next door but not in Missouri: the prairie rattlesnake (Iowa, Kansas, Nebraska and Oklahoma); the broad-banded copperhead (Kansas and Oklahoma); the western diamondback rattlesnake (Arkansas and Oklahoma). Listed next door and recorded in Missouri too, but too few times to list (records of any license): the eastern massasauga, recorded here only four times (listed in Illinois and Iowa). The most widely shared is the timber rattlesnake, listed in all eight bordering states.
Are there poisonous spiders in Missouri?
Does Missouri have black widows?
Yes. Two widow species are on the Missouri list: the northern black widow (31 records) and the southern black widow (7 records).
Does Missouri have brown recluse spiders?
Yes. The brown recluse is on the Missouri list, with 174 licensed records. Most of its licensed records come from Johnson County, St. Louis County and Boone County.
Brown recluse (Loxosceles reclusa)
Missouri has 174 licensed records of the brown recluse, which ranks the state 2nd of the 16 states where it reaches our threshold. Its observation records in Missouri run mostly April through October, peaking in July; most licensed records come from Johnson County, St. Louis County and Boone County. Range in other states and photos: Brown recluse profile.
Northern black widow (Latrodectus variolus)
Missouri has 31 licensed records of the northern black widow, which ranks the state 6th of the 30 states where it reaches our threshold. Its observation records in Missouri run mostly April through October, peaking in June; most licensed records come from Boone County, Texas County and Greene County. Range in other states and photos: Northern black widow profile.
Southern black widow (Latrodectus mactans)
Missouri has 7 licensed records of the southern black widow, which ranks the state 18th of the 22 states where it reaches our threshold. Range in other states and photos: Southern black widow profile.
More for Missouri
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.