The hobo spider and the giant house spider are close relatives that look remarkably similar, which is exactly why so many people confuse them. Both are funnel-web spiders in the family Agelenidae, both share the same genus (Eratigena), and both show up in homes across the Pacific Northwest. But they differ in size, climbing ability, and one detail that matters most to people: whether they pose any real danger.
Why They’re So Easy to Confuse
These two spiders were both originally classified in the genus Tegenaria. A 2013 molecular analysis revised the taxonomy of European funnel-web spiders and moved both into the newly created genus Eratigena. The hobo spider is Eratigena agrestis; the giant house spider is Eratigena atrica. That close genetic relationship explains why they share so many traits: long legs, brown coloring, fast running speed, and the same style of funnel-shaped web.
Both species build sheet webs with a funnel or tube-shaped retreat, typically in dark, sheltered spots like rock piles, woodpiles, foundation cracks, and basement corners. The spider sits at the narrow end of the funnel and rushes out when prey stumbles onto the web. From a distance, their webs are virtually identical.
How to Tell Them Apart by Size
Size is the most reliable visual cue. The giant house spider lives up to its name. Including leg span, it can reach 3 to 4 inches across, making it one of the largest spiders you’ll encounter indoors in North America. The hobo spider is noticeably smaller, with a leg span closer to 1.5 to 2 inches and a body length of roughly half an inch.
If the spider you’re looking at seems alarmingly large, it’s more likely a giant house spider. If it’s a moderate-sized brown spider that you mainly notice because it’s fast, the hobo spider is a stronger possibility. That said, young giant house spiders can overlap in size with adult hobos, so size alone isn’t always conclusive.
Markings and Physical Details
Both spiders are brown with somewhat muted, chevron-like markings on the abdomen, which is part of what makes visual identification so frustrating. The giant house spider tends to have more distinct, darker patterning on its legs and abdomen, while the hobo spider’s markings are often more uniform and less contrasting. Neither species has the bold, obvious markings you’d see on something like a garden spider.
One detail that entomologists use involves the pedipalps, the small appendage-like structures near the mouth. In male hobo spiders, the pedipalps have two prongs, while male giant house spiders have only one. This requires close inspection (often under magnification) and only works for males, so it’s not especially practical for someone staring at a spider in their bathtub. For a confident identification, capturing the spider and submitting it to a local university extension service is the most reliable option.
Behavior and Movement
Both species are swift runners, which is their primary defense. Giant house spiders are famously fast and will sprint away when startled rather than stand their ground. Hobo spiders are also quick but have a notable limitation: they struggle to climb smooth surfaces. Painted walls, porcelain tubs, and plastic sinks are essentially traps for them. If you find a brown spider stuck in your bathtub or sink and it can’t climb out, that’s a strong behavioral clue pointing toward a hobo spider. Both species can climb textured surfaces like carpet and fabric without difficulty.
Males of both species wander in late summer and fall, searching for females from August through October. This is the peak season for finding either spider indoors. They end up in basements, ground-floor rooms, shoes left on the floor, and bedding that touches the ground. Mated females produce one to four egg sacs starting in September. Males die shortly after mating.
Are Either of These Spiders Dangerous?
This is the question driving most searches, and the answer has changed significantly over the years. The hobo spider was long considered medically significant, with early reports suggesting its bite could cause tissue death similar to a brown recluse. The CDC even listed it as a venomous spider of concern for a time. However, more recent research has largely debunked this reputation. Studies failed to consistently reproduce necrotic wounds from hobo spider venom, and the CDC removed it from its list of dangerous spiders. Many of the original cases attributed to hobo spider bites likely involved other causes, including bacterial infections.
The giant house spider’s venom poses essentially no risk to humans. Bites are rare because these spiders prefer to flee, and when bites do occur, the effects are mild. The venom is designed for subduing insect prey and isn’t potent enough to cause significant harm to people. The only exception would be someone with a specific allergy to spider venom, which is uncommon.
In practical terms, neither spider should cause you alarm. A bite from either one, if it happens at all, is comparable to a mild bee sting for most people.
Where You’ll Find Each Species
Both spiders are found throughout the Pacific Northwest, including Washington, Oregon, Idaho, and parts of Utah and British Columbia. They’re originally European species that established themselves in North America. The giant house spider has a somewhat broader range and is more commonly found inside homes, particularly in basements and garages. The hobo spider is often found outdoors in rock piles, retaining walls, and tall grass, though it does enter homes, especially during fall mating season.
An interesting ecological detail: giant house spiders may actually help keep hobo spider populations in check. The two species compete for similar habitat, and the larger giant house spider is known to prey on hobos. In areas where giant house spider populations are well established, hobo spiders tend to be less common indoors.
Quick Comparison
- Size: Giant house spiders reach 3 to 4 inches across; hobo spiders top out around 2 inches.
- Climbing: Giant house spiders can scale smooth walls; hobo spiders get stuck on slick surfaces.
- Danger: Neither species is considered medically significant. Giant house spider venom is harmless to humans, and the hobo spider’s reputation for causing necrotic bites has been largely discredited.
- Markings: Giant house spiders tend to have more pronounced leg banding and abdominal patterns. Hobo spiders have more uniform, low-contrast coloring.
- Web: Both build funnel webs in sheltered, ground-level locations.
- Season: Both are most commonly seen indoors from August through October when males wander looking for mates.