The Hobo Spider (Eratigena agrestis) is one of the most misunderstood pests in the Intermountain West. Often blamed for "flesh-eating" bites, the Hobo is actually a shy, lightning-fast spider simply looking for a place to stay warm as the Utah summer fades.
Hobo spiders are notorious for being difficult to identify with the naked eye because they look like many other brown spiders in Utah.
The LegsHobo spiders have solid, uniform brown legs. If you see distinct dark stripes or "rings" on the legs, you are likely looking at a harmless Grass Spider.
The BodyThey have a herringbone or "V-shaped" pattern on their abdomen, but it is often faint and brownish-gray.
The WebThey are "funnel-web" weavers. They build a flat, horizontal sheet of silk that tapers into a funnel-shaped "retreat" in a corner or crevice.
In Utah, Hobo spiders are primarily outdoor dwellers, but they become an indoor "pest" during a very specific window of time.
The August MigrationAugust and September are "Hobo Season" in Utah. This is when males leave their outdoor webs to wander in search of mates, often entering basements through gaps in screens or under doors.
The "Sink Trap"Hobos are not good at climbing smooth, vertical surfaces. Homeowners often find them in bathtubs or sinks—not because they came up the drain, but because they fell in and couldn't climb out.
Low-Level LivingYou will rarely find a Hobo spider on your ceiling. They are ground-dwellers that prefer the dark, humid environment of crawlspaces and window wells.
Is the bite necrotic (flesh-eating)?Modern research has found no evidence that Hobo spider venom causes the skin-rotting lesions once attributed to them. A bite is typically no more painful than a wasp sting.
Are they aggressive?No. Their name agrestis means "of the fields," not "aggressive." They prefer to flee into their funnel rather than fight.
Do they have a violin on their head?No. That is a trait of the Brown Recluse, which is extremely rare in Utah.
