The Hobo spider is a highly poisonous (venomous) and dangerous spider, but not because it's aggressive. The "Hobo" has very poor sight and sees only about one or two meters. When disturbed by light or movement it normally remains still. If a Hobo senses danger it runs, it can't really see so sometimes it runs towards a person. If it runs towards you it's probably safest just to step aside. Sometimes the hobo spider is called the aggressive house spider. This is misleading because it's a "non-aggressive" spider. It is however very fast and its rapid movements might be interpreted as aggressive. It's an unpopular spider because it is mistaken for the seemingly more aggressive Brown Recluse Spider. It is indigenous to western and central Europe, but is now also found in the northwestern USA and southwestern Canada. It has recently spread to southern Alaska.

The Hobo spider are brown and measure around 1 to 2 cm in length. Their legs have short hairs and their abdomens have some shaped markings. Males have two palps looking like gloves, which are not found in females. Females tend to have a larger abdomen when compared to males.

Hobo spider bites are not known to be fatal to healthy humans. The necrosis in purported cases is similar to, but more mild than, that caused by the brown recluse spider, and in severe cases can take months to heal. Quite a large percentage of hobo spider bites are so-called dry bites. No venom is injected into the prey during a dry bite and its thought that 50 percent of bites on humans are dry bites. The reason for this may be that most bites from the Hobo are very fast and a defensive response from the spider. This might happen when the spider gets trapped between skin and something else and needs a fast way of solving the problem. Multiple bites do also occur in situations when the first bite doesn't achieve anything in terms of improving the situation of the spider.