Hobo spiders have long been prevalent in Montana and are one of the most commonly encountered spiders in homes across the state. Despite their fearsome reputation, these funnel-web spiders are far less dangerous than many Montanans believe. Here’s what you need to know about identifying them, understanding the real risk, and dealing with them in your home.
Where Hobo Spiders Live in Montana
Hobo spiders (Eratigena agrestis) are well established throughout Montana, particularly in urban and suburban areas. Originally from Europe, they spread across the Pacific Northwest decades ago and have been a fixture in Montana homes and yards ever since. They belong to the funnel-web weaver family, building flat, sheet-like webs with a funnel-shaped retreat at one end. You’ll find these webs in sheltered, ground-level spots: along foundations, in window wells, behind stored boxes in garages, in crawl spaces, and between retaining wall stones.
Hobo spiders are poor climbers, so encounters tend to happen at ground level. Males wander in search of mates during late summer and early fall, roughly August through October. This is when they most often end up indoors, stumbling into shoes, clothing left on the floor, or bedding that touches the ground. That wandering behavior is the main reason people come across them, not because the spiders are seeking out human spaces.
How to Identify a Hobo Spider
Hobo spiders are medium-sized, with a body length of roughly half an inch to three-quarters of an inch and a leg span of one to two inches. The front body section is brown with darker brown markings, and the legs are uniformly brown. The abdomen has a pattern of chevron-shaped yellowish markings on a grey background, though this pattern can be hard to see without magnification and is most visible on younger spiders.
The single most useful field identification tip: hobo spiders do not have dark bands on their legs. Many similar brown spiders in Montana, including the giant house spider and domestic house spider, display obvious banding or striping on their legs. If you see a brown, medium-sized spider with clearly banded legs, it is almost certainly not a hobo spider.
Beyond that, reliable identification gets difficult without a microscope. Hobo spiders have feather-like hairs (called plumose setae) lying flat against their legs, eight eyes arranged in two rows, and specific features on their mouthparts and reproductive structures that separate them from close relatives. In practice, even experienced naturalists struggle to tell hobo spiders from domestic house spiders and giant house spiders with the naked eye. If identification matters to you, capturing the spider in a jar and bringing it to your local Montana State University Extension office is the most reliable route.
Are Hobo Spiders Actually Dangerous?
For years, hobo spiders were labeled as medically significant, with claims that their bites caused necrotic skin lesions similar to those of brown recluse spiders. That reputation has largely collapsed. The CDC removed the hobo spider from its list of venomous spiders of medical concern, and the scientific consensus has shifted substantially. The original studies linking hobo spider venom to tissue death were conducted on rabbits, and subsequent research in humans failed to replicate those results. In Europe, where hobo spiders have coexisted with people for centuries, they have never been considered dangerous.
A hobo spider bite can still hurt. Like most spider bites, it may produce localized redness, mild swelling, and discomfort similar to a bee sting. But the dramatic, spreading wounds once attributed to hobo spiders were likely caused by bacterial infections, other medical conditions, or in some cases, entirely different spiders that were never actually identified.
It’s also worth noting that brown recluse spiders, which genuinely do cause necrotic wounds, are not native to Montana. According to Montana State University, no brown recluse has ever been positively identified in the state by a trained arachnologist. Many “brown recluse bites” diagnosed in Montana and other western states are misidentifications, often of skin infections like MRSA or other conditions entirely unrelated to spiders.
What to Do if You’re Bitten
If you suspect a spider bite, clean the area with mild soap and water and apply antibiotic ointment to prevent infection. A cool compress, 15 minutes per hour using a clean damp cloth or ice pack, helps with pain and swelling. Elevate the area if possible and use over-the-counter pain relievers or antihistamines for itching. Watch the bite over the following days for signs of worsening redness, spreading warmth, or discharge, which would suggest a secondary infection rather than venom effects.
Spiders Commonly Confused With Hobo Spiders
Montana is home to several brown spiders that get mistaken for hobo spiders regularly. The giant house spider is the most common lookalike. It’s larger, faster, and actually displaces hobo spiders in areas where the two overlap. It has conspicuous banding on its legs, which hobo spiders lack. The domestic house spider is smaller but builds similar funnel webs and shares the same general brown coloring. Again, leg banding is your best quick distinction.
Wolf spiders are another frequent source of confusion. They’re brown, ground-dwelling, and common in Montana homes. However, wolf spiders don’t build webs at all. They’re active hunters, and they tend to be stockier and faster-moving than hobo spiders. If you see a brown spider sprinting across your floor without a web nearby, it’s more likely a wolf spider.
Keeping Hobo Spiders Out of Your Home
Because hobo spiders are ground-level wanderers, prevention focuses on sealing entry points and reducing habitat near your foundation. Caulk gaps around ground-floor windows, doors, and utility penetrations. Install or repair door sweeps, especially on garage doors. Move firewood, rock piles, and dense vegetation away from the foundation, since these provide the sheltered, moist environments hobo spiders prefer for web-building.
Inside, reduce clutter at floor level in basements, garages, and storage areas. Sticky traps placed along walls and in corners are effective for monitoring and catching wandering males during the late summer mating season. Shake out shoes, gloves, and clothing that has been sitting on the floor, particularly in garages or basements, before putting them on. These simple habits matter far more than chemical treatments, since pesticide sprays have limited effectiveness against spiders that walk over treated surfaces on the tips of their legs.
If you’re finding hobo spiders regularly indoors, it usually means there’s a healthy population just outside your foundation. Addressing the exterior habitat and sealing entry points will do more than any indoor treatment to reduce encounters over time.