The hobo spider is a funnel-building spider. In the past, people believed its bite and venom were dangerous. However, scientists now believe this is not the case, and symptoms of a hobo spider bite are unclear.
Confirmed cases of hobo spider bites are rare. When there has been evidence of a hobo bite, the consequences were not serious.
People may believe they have been bitten by a hobo spider when the bite comes from another species, such as a brown recluse spider. However, a bacterial, fungal, or viral infection can cause similar symptoms.
A 2011 study that looked at various ways this spider’s venom might affect a person concluded that the hobo spider “is not a spider of medical concern.”
Some people have interpreted its Latin name — Tegenaria agrestis — to mean that it is aggressive. In fact, agrestis means that it comes from a rural area.
Hobo spiders get their common name from the belief that they spread throughout the United States by hitching lifts with people as they traveled along the highways.
The spiders came from Europe in the 1930s and are currently present in around six states in the Pacific Northwest.
According to the National Pest Management Association, the spider has:
- a light to medium brown back with a dark stripe pattern on it
- solid light brown legs without bands
- an oblong abdomen
- spinnerets that are visible from above
It measures 2.5–4.5 centimeters (cm) across, including its legs. Its body ranges from 0.8 -1.4 cm in length.
Hobo spiders build funnel webs with an escape tunnel at the back that often goes into a crack or other protected area. They are not good climbers, so they usually stay near ground level. They like dark, damp spaces.
Mating season lasts from June to October. At this time, male hobos may enter ground structures of buildings as they roam around and look for a mate. They do not live inside buildings.
A hobo spider is unlikely to bite except when catching prey or in self-defense, for example, if it becomes trapped against a person’s skin.
Very few studies have looked at confirmed hobo spider bites. For this reason, experts are not sure exactly what the symptoms are.
Past studies have linked a range of effects to hobo spider bites. However, experts now believe that most of these effects came from other spiders, notably the brown recluse.
It now seems most likely that the initial bite from a hobo spider will cause a slight prick or sting, and that minor skin irritation may follow.
Not many researchers have focused on an identified hobo bite. In a single study, a person experienced some minor pain and redness with a hobo bite, but these disappeared after 12 hours.
Some people have reported tissue death (necrosis) after a hobo spider bite. However, the authors of this study did not find any evidence to support this.
Some insects and spiders can introduce bacteria into the body when they bite. The hobo does not appear to do this.
What are the symptoms of a dangerous spider? Learn more here.
There is no specific treatment for a hobo spider bite.
However, the following tips from the
- Stay calm.
- Try to identify the spider. If possible, take a photo or capture the spider in a container.
- Wash the area with soap and water.
- If swelling occurs, apply ice or a cold, damp cloth.
- Raise the bite area, if possible.
- Seek medical help immediately.
The CDC
However, various bites and stings can trigger an allergic reaction in some people. If a person experiences a bothersome reaction, a doctor may recommend an antihistamine cream.
If sudden or severe symptoms occur, this may be a sign of an allergic reaction. The person should seek immediate medical attention, especially if they start to have:
- swelling
- hives
- difficulty breathing
These can be signs of anaphylaxis, which is a severe and potentially life-threatening reaction.
Learn more here about how to recognize anaphylaxis and what to do if it happens.
Anyone concerned about changes to their skin, from a spider bite or an unknown cause, should see a doctor.
If a person knows a spider has bitten them, they should take a photo of the spider or collect it in a sealed container to show the doctor.
To enable proper identification, they should bring the spider alive and avoid damaging it.
Hobo spiders rarely bite people. If they do, the effects are unlikely to be severe or long lasting.
To avoid hobo spiders entering the home, people can:
- seal any cracks around the house
- keep all rooms — including garages and basements — clean and free of clutter
- store shoes and other items above ground
- take care when moving things that have been standing for a long time