For many people spiders instill an instant feeling of terror. They are creepy, ugly-looking little things, and the very sight of one will send shivers up the spine of the average person. However, more often than not the fear is unwarranted. While all spiders are venomous, many spiders' mouths are too small to bite a human. Out of the creatures that are large enough to bite, very few have enough venom to cause any significant damage. Here in the Pacific Northwest, and more specifically the states of Oregon and Washington, there are only two species of spiders considered dangerous to humans: the western black widow and the hobo spider.
The black widow is perhaps the most well-known and wide-spread spider in the United States. Even though it is considered to be the most venomous spider in the United States, a black widow bite is rarely fatal. While it is recommended to seek immediate medical help if you believe that you have been bitten by a black widow, the most serious cases are generally found only in small children, the elderly, or people with already pre-existing medical conditions. Black widow venom is a neurotoxin, meaning that it attacks the nervous system. Often times the bite itself is not actually noticed, as it is generally not painful, and leaves a very small mark. Common symptoms include muscle cramping, nausea, fever, trouble breathing, and tremors. Black widows are usually found in dark, dry places such as: rock piles, piles of firewood, attics, and crawl spaces. The female is much larger than the male, growing to a leg span of up to two inches, and is characterized by the bright red hourglass shape beneath its abdomen. The rest of the arachnid is a glossy black color.
The hobo spider, also commonly known as the aggressive house spider, is not considered as dangerous as the black widow. The name aggressive house spider is actually somewhat deceiving, as this particular species is no more aggressive than most other species. It is believed that the common name was derived from a misinterpretation of the creature's Latin name, Tegenaria agrestis. Agrestis, however, does not mean aggressive; it actually means 'of the fields', which is where this pest is most commonly found. A hobo spider bite has never been known to cause death. Their venom is necrotic, and is often confused with the bite of the brown recluse, however, the brown recluse is not found in Washington or Oregon. The bite of the hobo spider causes a blister, which breaks open after a day or so, leaving a nasty lesion, and can take quite a long time to heal. The hobo spider is a pretty ordinary looking arachnid.