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Be careful

Dark fishing spider

Dolomedes tenebrosus
Also called fishing spider, dock spider, tree-dwelling fishing spider

Alarming size, low risk: it is shy and rarely bites, but a bite can hurt about like a bee or wasp sting.

Dark fishing spider, photo 1
Photo: Andrew Meeds, CC BY 4.0, via iNaturalist
SizeLarge females about 25–32 mm (1 to 1 1/4 inches) body length, with a leg span up to about 75–90 mm (3 to 3 1/2 inches); males are much smaller
Where in the houseBasement, garage, windows and walls, outside near the house
WhenSpring and summer, with occasional indoor visitors into fall.

Check these features

  1. Very large, flattish, hairy spider in mottled gray and brown, colored like tree bark
  2. Long legs held spread out flat, with light and dark bands
  3. Abdomen usually marked with a few dark W- or chevron-shaped bands
  4. Often rests head-down on tree trunks, decks, siding or walls
  5. Builds no web; female carries a large round egg sac in her jaws

Bites and stings

Bites are rare because this spider usually runs away. If one does bite, expect sharp pain about like a bee or wasp sting, with possible redness and swelling. Wash the spot and use a cold pack; get medical care if pain or swelling keeps getting worse, the area looks infected, or there are signs of an allergic reaction (call 911 for trouble breathing or swelling of the face or throat).

What to do

  1. Give it space and don't grab it; cover it with a large bowl or container, slide stiff cardboard underneath, and carry it outside.
  2. If bitten, wash the spot with soap and water and apply a cold pack.
  3. If it is in a basement or garage, open the outside door and gently herd it out with a broom.
  4. Keep an eye on the bite for spreading redness or signs of infection over the next couple of days.

Look-alikes

Carolina wolf spider and other wolf spidersWolf spiders are stockier with shorter legs, run on the ground, and carry the egg sac at the rear of the body; fishing spiders are flatter, longer-legged, banded, and usually sit on walls or trunks.
Brown recluseA recluse is far smaller (about 3/8 inch body), smooth and evenly tan with a violin mark and no leg bands; a dark fishing spider is several times larger, hairy and mottled.
Striped and six-spotted fishing spidersClose relatives that are similar in size or a bit smaller and usually live right at the water's edge; they are just as low-risk.
Huntsman spidersHuntsman spiders are also big and flat but are mostly a plain tan, found mainly in the far South and Gulf states, and move sideways like crabs.

Why it came inside

Unlike most fishing spiders it lives in wooded areas, often far from water, and hunts on trees, decks and house siding at night; it sometimes wanders in by accident, especially in homes near woods.

Keep it out

  • Fit door sweeps and weatherstripping, especially on doors near decks and wooded areas.
  • Seal gaps around windows, vents, pipes and the foundation with caulk.
  • Keep window and door screens in good repair.
  • Trim back branches and vines touching the house and move woodpiles away from walls.

What helps

Links go to Amazon search results so you can compare current options. As an Amazon Associate I earn from qualifying purchases. Always follow the product label.

Door sweep

Closes the gap under an exterior door. If you can see daylight under the door, bugs can get in.

See options on Amazon
Weatherstripping

Seals the gaps around doors and windows that let in drafts and bugs alike.

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Caulk and sealant

Silicone or siliconized acrylic caulk closes cracks around windows, pipes and baseboards. Bigger gaps need foam backer rod or expanding foam first.

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Screen repair kit

Patches or replaces torn window and door screens, one of the most common ways insects get in.

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Bug catcher

A long-handled catcher moves a spider or insect outside without you having to touch it.

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Sticky traps

Flat glue traps set along walls and in corners show what is moving through and where. Place them where pets and children can't reach.

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Sources

  1. Mississippi State University Extension
  2. University of Maine Cooperative Extension
  3. University of Minnesota Extension

Checked October 18, 2026. Rating backed by 2 sources. How we rate danger.