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Venomous snakes and spiders in Kansas

Kansas has six venomous snake species among the 44 snake species listed there: eastern copperhead, western massasauga, prairie rattlesnake, timber rattlesnake, northern cottonmouth and broad-banded copperhead. The eastern copperhead accounts for the most records (615), and venomous species make up 11% of all 14,740 licensed snake records in the state. On the spider side, four species are medically significant: brown recluse, western black widow, northern black widow and southern black widow.

6venomous snake species
4widow or recluse species
44snake species in all
16,386licensed records read
Bitten in Kansas? Call 911 for a venomous snakebite or any bite with trouble breathing. For advice on any bite or sting, call Poison Help at 1-800-222-1222 (free, 24/7, U.S.-wide). Do not cut the wound, suck out venom or use a tourniquet. General information, not medical advice. Do not handle or try to identify a snake or spider by this page; if unsure, treat it as venomous.

Venomous snakes of Kansas

Kansas's venomous snakes are three copperhead or cottonmouth species and three rattlesnake species. Together they account for 1,644 licensed records; the eastern copperhead alone has 37% of them, and the least recorded, the broad-banded copperhead, has 7.

Dangerous spiders of Kansas

Three widow species (Western black widow: 6 records, Northern black widow: 4 records, Southern black widow: 1 record) and one recluse species (Brown recluse: 84 records) are on the Kansas 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 Kansas?

Yes. One scorpion species is recorded in Kansas, from 113 licensed records: Striped bark scorpion (24 records). Every scorpion has venom; only the Arizona bark scorpion's sting is medically significant, and it is not on the Kansas list.

Striped bark scorpion
Striped bark scorpionCentruroides vittatus24 records in KS

Other snakes recorded most in Kansas

These eight account for 54% of all licensed snake records in Kansas; the most recorded, the ring-necked snake, alone for 18%.

All 44 snakes of Kansas →

Other spiders recorded most in Kansas

These eight account for 27% of all licensed spider records in Kansas; the most recorded, the bold jumper, alone for 6%.

All 94 spiders of Kansas →

When venomous snakes are out in Kansas

Observation records of venomous snakes in Kansas run mostly April through October, peaking in September with 25% of them. December through February together hold under 2% of the records, so venomous snakes in Kansas are rarely recorded in winter.

January: 0 observation records (0%)JanFebruary: 0 observation records (0%)FebMarch: 0 observation records (0%)MarApril: 22 observation records (9%)Apr9%May: 62 observation records (25%)May25%June: 13 observation records (5%)JunJuly: 31 observation records (12%)Jul12%August: 29 observation records (12%)Aug12%September: 63 observation records (25%)Sep25%October: 28 observation records (11%)Oct11%November: 4 observation records (2%)NovDecember: 0 observation records (0%)Dec

Season of each venomous snake

SpeciesMain seasonPeak monthWinter shareObservation records
Eastern copperheadApril through SeptemberSeptember0%97
Western massasaugaMay through OctoberMay0%45
Prairie rattlesnakeApril through OctoberJuly0%78
Source: GBIF observation records (CC0, CC BY) in Kansas by month, read 2026-09-29. Species with fewer than 30 observation records with a month are left out.

When spiders are most active in Kansas

Observation records of spiders in Kansas run mostly April through October, peaking in August with 20% of them. December through February together hold under 2% of the records, so spiders in Kansas are rarely recorded in winter.

January: 2 observation records (0%)JanFebruary: 10 observation records (1%)FebMarch: 31 observation records (3%)MarApril: 128 observation records (11%)Apr11%May: 143 observation records (12%)May12%June: 151 observation records (12%)Jun12%July: 186 observation records (15%)Jul15%August: 237 observation records (20%)Aug20%September: 211 observation records (17%)Sep17%October: 87 observation records (7%)Oct7%November: 17 observation records (1%)NovDecember: 5 observation records (0%)Dec

Counties with the most venomous snake records

Douglas County has the most records of venomous snakes in Kansas, 176, most of them of the eastern copperhead. Barton County and Marshall County follow.

#CountyRecordsMost recorded there
1Douglas County176Eastern copperhead
2Barton County102Western massasauga
3Marshall County97Eastern copperhead
4Miami County61Eastern copperhead
5Linn County59Eastern copperhead
6Barber County54Western massasauga
7Franklin County53Eastern copperhead
8Ellis County52Prairie rattlesnake
9Ellsworth County49Western massasauga
10Jefferson County48Eastern copperhead
Source: GBIF licensed records by county (GADM level 2), read 2026-09-29. Sum over the venomous species above.

Where in Kansas are snakes recorded most?

Cowley County leads with 1,536 records (10%), followed by Douglas County and Chase County; the top five counties hold 32% of the total. 105 of Kansas's 105 counties have at least one licensed snake record.

#CountyRecordsShare
1Cowley County1,53610.4%
2Douglas County1,2158.2%
3Chase County7315.0%
4Ellis County6574.5%
5Russell County5163.5%
6Cherokee County4393.0%
7Riley County4202.8%
8Barber County3312.2%
9Johnson County3302.2%
10Meade County3112.1%
11Marshall County3062.1%
12Bourbon County3052.1%
Source: GBIF licensed records by county (GADM level 2), read 2026-09-29. Counties with many records often have active naturalists or a museum nearby.

Are there poisonous snakes in Kansas?

Yes. Kansas has six venomous snake species on its list, the kind people usually call poisonous: eastern copperhead, western massasauga, prairie rattlesnake, timber rattlesnake, northern cottonmouth and broad-banded copperhead. Strictly, snakes are venomous (they inject venom), not poisonous (harmful to eat or touch).

Are there rattlesnakes in Kansas?

Yes. Three species are on the Kansas list: the western massasauga, the prairie rattlesnake and the timber rattlesnake, with 1,014 licensed records between them. Most licensed records of the western massasauga come from Barton County, Ellsworth County and Barber County.

Are there copperheads in Kansas?

Yes. Two species are on the Kansas list: the eastern copperhead and the broad-banded copperhead, with 622 licensed records between them. Most licensed records of the eastern copperhead come from Douglas County, Marshall County and Linn County.

Are there cottonmouths (water moccasins) in Kansas?

Yes. One species is on the Kansas list: the northern cottonmouth, with 8 licensed records.

Are there coral snakes in Kansas?

No. GBIF holds no coral snake record for Kansas under any license.

Eastern copperhead (Agkistrodon contortrix)

Kansas has 615 licensed records of the eastern copperhead, which ranks the state 4th of the 27 states where it reaches our threshold. Its observation records in Kansas run mostly April through September, peaking in September; most licensed records come from Douglas County, Marshall County and Linn County. Range in other states and photos: Eastern copperhead profile.

Western massasauga (Sistrurus tergeminus)

Kansas has 490 licensed records of the western massasauga, which ranks the state 1st of the 8 states where it reaches our threshold. Its observation records in Kansas run mostly May through October, peaking in May; most licensed records come from Barton County, Ellsworth County and Barber County. Range in other states and photos: Western massasauga profile.

Prairie rattlesnake (Crotalus viridis)

Kansas has 347 licensed records of the prairie rattlesnake, which ranks the state 5th of the 14 states where it reaches our threshold. Its observation records in Kansas run mostly April through October, peaking in July; most licensed records come from Ellis County, Logan County and Trego County. Range in other states and photos: Prairie rattlesnake profile.

Timber rattlesnake (Crotalus horridus)

Kansas has 177 licensed records of the timber rattlesnake, which ranks the state 6th of the 30 states where it reaches our threshold. Most of its licensed records in Kansas come from Douglas County, Marshall County and Franklin County. Range in other states and photos: Timber rattlesnake profile.

Northern cottonmouth (Agkistrodon piscivorus)

Kansas has 8 licensed records of the northern cottonmouth, which ranks the state 16th of the 16 states where it reaches our threshold. Range in other states and photos: Northern cottonmouth profile.

Broad-banded copperhead (Agkistrodon laticinctus)

Kansas has 7 licensed records of the broad-banded copperhead, which ranks the state 3rd of the 3 states where it reaches our threshold. Range in other states and photos: Broad-banded copperhead profile.

Harmless lookalikes in Kansas

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 Kansas.

What looks like a copperhead in Kansas

Copperheads: 622 licensed records in Kansas. Harmless species often taken for them are also on the state list: northern water snake (1,214), plain-bellied watersnake (304), eastern milksnake (245), central plains milksnake (195) and eastern hog-nosed snake (130). Together they have 2,206 licensed records, and the lookalikes are recorded 4 times as often.

What looks like a cottonmouth in Kansas

Cottonmouths: 8 licensed records in Kansas. Harmless species often taken for them are also on the state list: northern water snake (1,214), plain-bellied watersnake (304) and diamondback water snake (188). Together they have 1,706 licensed records, and the lookalikes are recorded 213 times as often.

What looks like a rattlesnake in Kansas

Rattlesnakes: 1,014 licensed records in Kansas. Harmless species often taken for them are also on the state list: gopher snake (632), Great Plains rat snake (238), plains hog-nosed snake (197) and eastern hog-nosed snake (130). Together they have 1,197 licensed records, and the two sides are recorded about equally.

What looks like a coral snake in Kansas

No coral snakes reach the Kansas list, and GBIF holds no coral snake record for Kansas under any license, so a snake taken for one here is most likely a harmless lookalike. Those recorded in the state: eastern milksnake (245), central plains milksnake (195) and long-nosed snake (67).

What looks like a widow spider in Kansas

Widow spiders: 11 licensed records in Kansas. Harmless species often taken for them are also on the state list: triangulate bud spider (26), common house spider (8) and boreal combfoot (5). Together they have 39 licensed records, and the lookalikes are recorded 4 times as often.

What looks like a recluse spider in Kansas

Recluse spiders: 84 licensed records in Kansas. Harmless species often taken for them are also on the state list: longbodied cellar spider (3). It has 3 licensed records, and here the venomous species are the more recorded side, 28.0 to 1.

How Kansas compares

By count of venomous snake species, Kansas ranks 8th of 50 states, level with Alabama, Nevada and South Carolina. Nationally, Arizona leads with 14 species; five list none.

Of the four states bordering Kansas, Oklahoma lists more venomous snake species (Kansas: 6 species; Oklahoma 8, Missouri 5, Nebraska 4, Colorado 3).

Venomous snakes listed next door but not in Kansas: the western diamondback rattlesnake (Oklahoma); the western rattlesnake (Colorado). Listed next door and recorded in Kansas too, but too few times to list (records of any license): the pygmy rattlesnake, recorded here only two times (listed in Missouri and Oklahoma). The most widely shared is the western massasauga, listed in all four bordering states.

Are there poisonous spiders in Kansas?

Does Kansas have black widows?

Yes. Three widow species are on the Kansas list: the western black widow (6 records), the northern black widow (4 records) and the southern black widow (1 record).

Does Kansas have brown recluse spiders?

Yes. The brown recluse is on the Kansas list, with 84 licensed records. Most of its licensed records come from Douglas County, Leavenworth County and Shawnee County.

Brown recluse (Loxosceles reclusa)

Kansas has 84 licensed records of the brown recluse, which ranks the state 6th of the 16 states where it reaches our threshold. Its observation records in Kansas run mostly March through August, peaking in July; most licensed records come from Douglas County, Leavenworth County and Shawnee County. Range in other states and photos: Brown recluse profile.

Western black widow (Latrodectus hesperus)

Kansas has 6 licensed records of the western black widow, which ranks the state 15th of the 18 states where it reaches our threshold. Range in other states and photos: Western black widow profile.

Northern black widow (Latrodectus variolus)

Kansas has 4 licensed records of the northern black widow, which ranks the state 20th of the 30 states where it reaches our threshold. Range in other states and photos: Northern black widow profile.

Southern black widow (Latrodectus mactans)

Kansas has 1 licensed record of the southern black widow, which ranks the state 20th of the 22 states where it reaches our threshold. Range in other states and photos: Southern black widow profile.

More for Kansas

GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.

About these numbers

A species is listed for a state once GBIF holds at least 10 records of it located inside the state by coordinates, under any license. Every count, share, month and county shown is computed only from records published under CC0 or CC BY, so a listed species can show few or no counted records. Monthly patterns show when people record snakes and spiders, which also reflects when people are outdoors. Venomous status follows taxonomy: pit vipers and coral snakes; widow and recluse spiders; the Arizona bark scorpion. Records filed under older names count for the species they belong to today. Full methodology.