Snakes and spiders in Will County, Illinois
Will County, home of Joliet, has 9 snake and 32 spider species on record, from 166 licensed snake and 552 spider records. No venomous snake or spider reaches the county list, but the northern cottonmouth, the eastern copperhead, the eastern massasauga, the timber rattlesnake and 3 more are on the Illinois list: treat any snake or spider like them as venomous until identified.
What snakes are in Will County?
In all, 9 snake species are on the Will County list. The most recorded are the plains garter snake (42), the eastern fox snake (27) and the common garter snake (26).
| # | Species | Records | Share of Illinois records |
|---|---|---|---|
| 1 | Plains garter snake Thamnophis radix | 42 | 17% |
| 2 | Eastern fox snake Pantherophis vulpinus | 27 | 33% |
| 3 | Common garter snake Thamnophis sirtalis | 26 | 6% |
| 4 | Smooth green snake Opheodrys vernalis | 21 | 39% |
| 5 | Northern water snake Nerodia sipedon | 20 | 8% |
| 6 | DeKay's brown snake Storeria dekayi | 19 | 6% |
| 7 | Queen snake Regina septemvittata | 5 | 20% |
| 8 | Eastern racer Coluber constrictor | 2 | 2% |
| 9 | Gopher snake Pituophis catenifer | 2 | 8% |
When are snakes out in Will County?
Observation records of snakes in Will County run mostly April through September, peaking in April with 27% of them; across Illinois the peak is October.
What spiders are in Will County?
In all, 32 spider species are on the Will County list. The most recorded are the wetland giant wolf spider (40), Eridantes erigonoides (14) and the nursery web spider (14). Will County holds more than half of all Illinois records of the zebra thin sheetweaver.
Same family (Linyphiidae): Frontinella pyramitela
Related species: Bathyphantes pallidus
| # | Species | Records | Share of Illinois records |
|---|---|---|---|
| 1 | Wetland giant wolf spider Tigrosa helluo | 40 | 28% |
| 2 | Eridantes erigonoides | 14 | 11% |
| 3 | Nursery web spider Pisaurina mira | 14 | 11% |
| 4 | Notch-tipped shield sheetweaver Bathyphantes alboventris | 13 | 42% |
| 5 | Bold jumper Phidippus audax | 12 | 3% |
| 6 | Pale sheetweb weaver Bathyphantes pallidus | 12 | 6% |
| 7 | Dark fishing spider Dolomedes tenebrosus | 11 | 12% |
| 8 | Greater ant-mimic corinne spider Phrurotimpus borealis | 11 | 7% |
| 9 | Plump dictynid spider Argenna obesa | 11 | 48% |
| 10 | Zebra thin sheetweaver Tenuiphantes zebra | 10 | 83% |
| 11 | Sixspotted fishing spider Dolomedes triton | 9 | 18% |
| 12 | Familiar jumping spider Platycryptus undatus | 8 | 7% |
| 13 | Arabesque orbweaver Neoscona arabesca | 7 | 5% |
| 14 | Spotted orbweaver Neoscona crucifera | 7 | 5% |
| 15 | Banded garden spider Argiope trifasciata | 6 | 4% |
| 16 | Flea jumping spider Naphrys pulex | 6 | 11% |
| 17 | Parson spider Herpyllus ecclesiasticus | 6 | 9% |
| 18 | Whitebanded crab spider Misumenoides formosipes | 5 | 5% |
| 19 | Zebra spider Salticus scenicus | 5 | 3% |
| 20 | Brilliant jumping spider Phidippus clarus | 4 | 3% |
| 21 | Orchard orbweaver Leucauge venusta | 4 | 4% |
| 22 | Paraphidippus aurantius | 4 | 7% |
| 23 | Spined micrathena Micrathena gracilis | 3 | 3% |
| 24 | Thin-spined jumping spider Tutelina elegans | 3 | 10% |
| 25 | Black-and-yellow argiope Argiope aurantia | 2 | 2% |
| 26 | Triangulate bud spider Steatoda triangulosa | 2 | 3% |
| 27 | American green crab spider Misumessus oblongus | 1 | 2% |
| 28 | Asian wall jumper Attulus fasciger | 1 | 1% |
| 29 | Dysdera crocata | 1 | 2% |
| 30 | Furrow orbweaver Larinioides cornutus | 1 | 1% |
| 31 | Garden spider Araneus diadematus | 1 | 4% |
| 32 | Marbled orbweaver Araneus marmoreus | 1 | 3% |
When are spiders out in Will County?
Observation records of spiders in Will County run mostly April through September, peaking in June with 24% of them; across Illinois the peak is September.
What stands out in Will County
Species for which Will County holds a large share of all Illinois records: the plump dictynid spider, 48% (11 of 23); the notch-tipped shield sheetweaver, 42% (13 of 31); the smooth green snake, 39% (21 of 54); the eastern fox snake, 33% (27 of 83); the wetland giant wolf spider, 28% (40 of 141); the plains garter snake, 17% (42 of 250).
Common in Illinois, not on the Will County list
Among the snakes most recorded across Illinois, these do not reach the county list: the northern cottonmouth (259 statewide), the ring-necked snake (87 statewide), the eastern rat snake (86 statewide), the eastern wormsnake (85 statewide), the prairie kingsnake (82 statewide) and the plain-bellied watersnake (72 statewide). Few records here can mean the species is rare in the county, or that few people have looked.
Among the spiders most recorded across Illinois, these do not reach the county list: Pardosa saxatilis (545 statewide), the brown recluse (313 statewide), Piratula minuta (208 statewide), the brush-legged split wolf spider (192 statewide), the tan crab spider (187 statewide) and the shiny wolf spider (170 statewide). Few records here can mean the species is rare in the county, or that few people have looked.
Harmless lookalikes in Will County
No copperheads reach the county list, but the eastern copperhead is on the Illinois list: treat any snake like it as venomous until identified. Harmless species often taken for them here: the northern water snake. No cottonmouths reach the county list, but the northern cottonmouth is on the Illinois list: treat any snake like it as venomous until identified. Harmless species often taken for them here: the northern water snake. No rattlesnakes reach the county list, but the eastern massasauga and the timber rattlesnake are on the Illinois list: treat any snake like them as venomous until identified. Harmless species often taken for them here: the eastern fox snake and the gopher snake. No widow spiders reach the county list, but the southern black widow and the northern black widow are on the Illinois list: treat any spider like them as venomous until identified. Harmless species often taken for them here: the triangulate bud spider.
Will County among Illinois counties
By licensed snake records Will County ranks 4th of 90 Illinois counties with any.
Other Illinois counties with their own page: Union County, Cook County, Champaign County, Jo Daviess County, Mason County, Iroquois County, Effingham County and Lee County.
The whole state: venomous species in Illinois, all snakes, all spiders.
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.