Most spiders you’ll find inside a Tennessee home are harmless. The American house spider and the cellar spider account for the majority of indoor sightings, and neither poses a medical threat. Tennessee is, however, home to both the brown recluse and the black widow, so knowing what you’re looking at matters.
American House Spider
The American house spider is the one you’re most likely to encounter indoors. It’s about the size of a nickel with its legs outstretched, brown and tan with darker brown patterns, and has a rounded, globe-shaped abdomen. Females range from about 3/16 to 1/3 of an inch in body length, while males are smaller and darker.
These spiders build messy, tangled cobwebs in corners, along window frames, under eaves, and between any two adjoining surfaces. They’re the primary source of the cobwebs that accumulate in garages, sheds, basements, and attics. Multiple spiders often colonize the same area, building nearly connected webs that can cover large stretches of wall space. Their bites are harmless to most people.
Cellar Spiders
Cellar spiders are the other extremely common indoor spider in the region. They’re easy to recognize: small, thin bodies with disproportionately long, delicate legs, spanning about the size of a half-dollar when outstretched. Their color ranges from light tan to gray with some darker markings. You’ll find them in basements, crawl spaces, and quiet corners where they hang upside down in loose, irregular webs. Like the American house spider, their bites are harmless.
Southern House Spiders and Other Lookalikes
Southern house spiders are common in Tennessee and are frequently mistaken for brown recluses because of their similar brown coloring. The key differences: southern house spiders have eight eyes grouped closely together (brown recluses have only six, arranged in three pairs forming a semicircle), they lack the violin-shaped marking on the back, and they have extended, thin pedipalps near the mouth.
Wolf spiders also turn up indoors, especially in fall. They’re larger and more intimidating than most house spiders, but they’re identifiable by the dark stripes on their bodies and legs. They don’t build webs and instead hunt on the ground. Like cellar spiders and house spiders, wolf spider bites aren’t medically significant for most people.
Brown Recluse Spiders in Tennessee
Tennessee is one of 16 states where brown recluse spiders are established and can be genuinely common inside homes. One well-known study documented more than 2,000 brown recluses collected from a single home over six months, yet the residents hadn’t been bitten in six years. The spiders are reclusive by nature and rarely bite unless pressed against skin.
A brown recluse is about the size of a quarter with legs extended. Its body is a uniform light yellowish-brown to dark brown, with no stripes or bands on the legs. The signature feature is a dark, violin-shaped marking on the top of the body, with the “neck” of the violin pointing toward the rear. The other reliable identifier is the eye pattern: six eyes in three pairs forming a semicircle, rather than the eight eyes most spiders have.
They prefer dark, warm, dry spaces: attics, closets, basements, woodpiles, boxes in storage, old tires. Inside homes, they often hide in undisturbed clothing, behind picture frames, or in cardboard boxes that haven’t been moved in a while.
A brown recluse bite may initially feel like mild stinging or nothing at all. Over the next two to eight hours, the site can become painful and itchy, sometimes developing a distinctive “bull’s-eye” pattern: a blue or purplish center surrounded by a grayish ring and then a red outer ring. In some cases, 24 to 72 hours after a bite, a person may develop fever, rash, and muscle pain. Children under 12 are at higher risk for a serious complication in which the venom destroys red blood cells. Any spreading discoloration, worsening pain, or systemic symptoms like fever warrant a trip to the emergency room.
Black Widow Spiders in Tennessee
Black widows are present throughout Tennessee, typically in dark, undisturbed outdoor and semi-outdoor spaces: crawl spaces, water meter boxes, firewood piles, and the insides of stored boxes. They’re glossy black with the well-known red or orange hourglass marking on the underside of the abdomen.
The bite itself feels like a pinprick and may produce only minor redness that fades quickly. The real concern is what follows. Two to four hours later, systemic effects can set in: headache, nausea, vomiting, changes in heart rate and blood pressure, and painful muscle cramping or rigidity. These symptoms require hospital monitoring and treatment.
How to Tell Dangerous From Harmless
If you’ve found a brown spider in your house and want to rule out a brown recluse, check three things. First, look at the legs: a brown recluse has uniformly colored legs with no stripes, bands, or spines. Second, look for the violin marking on the top of the body behind the eyes. Third, if you can get close enough or capture it, count the eyes. Six eyes in three pairs is a brown recluse. Eight eyes is something else.
American house spiders have rounder bodies with distinct mottled patterns. Cellar spiders are immediately recognizable by their extraordinarily long, thin legs relative to their tiny bodies. Wolf spiders are bulkier with visible leg stripes. None of these have the violin marking or the six-eye arrangement.
Peak Spider Season
Indoor spider sightings in Tennessee peak in August and September. Warm days paired with cooler nights push spiders indoors, and this period overlaps with mating season for many species. Male spiders wander more while searching for mates, which is why you suddenly see more of them crossing floors and walls. Activity stays relatively high through October, then drops off from November through May.
Keeping Spiders Out of Your Home
Regular, thorough cleaning is the single most effective strategy. A vacuum cleaner or broom removes spiders, webs, and egg sacs, and destroying egg sacs is especially important since each one can contain hundreds of young spiders. Reducing clutter in basements, attics, garages, and closets makes those spaces less inviting, since spiders prefer quiet, undisturbed areas.
Outside the house, move firewood, stacked materials, and debris away from the foundation. Trim back shrubs, vines, and tree branches that touch the building, as these give spiders a direct bridge to your walls and roof. Install tight-fitting window screens and door sweeps to block entry points.
Switching outdoor lights to yellow or sodium vapor bulbs helps indirectly. These bulbs attract fewer night-flying insects, which means less food to draw spiders to your doorways and porches. For additional protection during warmer months, a perimeter insecticide spray around door thresholds, garage entrances, foundation vents, and the bottom edge of siding can reduce spider migration indoors. These treatments typically need to be reapplied monthly or every other month through the active season.
What to Do After a Spider Bite
For bites from harmless species, clean the area with soap and water, apply a cool damp cloth for 15 minutes each hour to reduce swelling, and use over-the-counter pain relievers or antihistamines as needed. Applying antibiotic ointment three times a day helps prevent infection. If possible, elevate the bite area.
Seek medical care right away if you know or suspect the bite came from a brown recluse or black widow, if you develop severe pain or stomach cramping, if the wound is growing larger, if the surrounding skin turns red, purple, or brown with spreading streaks, or if you have any difficulty breathing or swallowing.