How to Identify Household Spiders

Numerous species of spiders can be found in your home. Most of these spiders are harmless and are very timid and non-aggressive. There are, however, several spiders that could pose a threat to the health of your family. Learning to properly identify these spiders can help you either avoid injury or get speedy medical treatment if it is needed.

Things You'll Need

• Magnifying glass
• Jar (with lid)

Instructions

1. Watch for a dark violin shape just behind the head. This is the distinctive mark of the Brown Recluse Spider. This species is aggressive and venomous. In certain instances, the bite of the Brown Recluse can be fatal. This spider is found throughout the United States, but its heaviest population is in the southern states. An adult Brown Recluse will measure from 1/4 inch up to 3/4 inch. They are brown with the aforementioned violin shape just behind the head. The Brown Recluse is unusual, with six eyes rather than the eight found on other spiders. The bite area it leaves could have significant tissue damage. Immediate medical attention and treatment should be sought by the victim.

2. Be on the lookout for a reddish hourglass figure or mark on the underside of a black spider. This mark belongs to the Black Widow Spider. This spider is extremely venomous, but is normally non-aggressive. It will bite when cornered or trapped against your flesh, such as in clothing or footwear. The Black Widow spider is found throughout the United States and most of North America. A single bite can be fatal. The most susceptible victims are the very young and the elderly. The venom attacks the nervous system and can cause extreme pain, headache, nausea and vomiting. The adult female Black Widow will measure 1/2 inch and will be shiny black. (Note: Only the female of the species is venomous.) A red or reddish-yellow marking on the spider's underside will normally be in the shape of an hourglass, but may appear only as a red dot. If you are bitten, seek immediate medical treatment. People with heart-related problems are at greater risk, and may require hospitalization.

3. Watch for boxing gloves. A Hobo Spider can be found in areas of the northwest and some mountain states. The adult Hobo spider will have a leg span of up to 2 inches. They are brown in color, and the males will have two large mouth parts (palpi) protruding from the front of its head that resemble boxing gloves. The bite of a Hobo spider is often painless but develops into a serious wound within 24 to 36 hours. A blister will develop and then break open, leaving an open, oozing wound. These spiders do not climb vertically, and are very rarely found above the ground floor of any structure.

4. Check your windows, toilets and light fixtures. The Black House Spider measures 1/2 inch in body length. This species has a velvet-textured body that will be black or dark brown in color. The Black House Spider likes to build webs in windows, toilets and bricks, and near light fixtures. The lights attract moths and other insects, which the spider will feed on. The bite of the Black House Spider is venomous, but is normally non-lethal. Some people may be more susceptible to this poison and will have serious symptoms. These could include vomiting, body pains and severe headaches. In these cases, medical treatment should be sought immediately.

5. Look out for the Union Jack. The Wolf Spider is a non-aggressive species that, while venomous, is generally nonlethal. The Wold Spider will have a body length of up to 1 inch or more. It is grayish to brown in color and has that very distinctive Union Jack on its back. The Wolf Spider is common in gardens, but will rarely be found indoors. While non-aggressive, the Wolf Spider will not hesitate to bite if provoked. While they are generally considered non-threatening to humans, any bite should be monitored and medical help sought if pain does not subside or additional symptoms appear.

Tips & Warnings

• Many spider bites are initially painless and are only noticed later. Often, it is uncertain if the wound is a result of a spider bite or that of another insect. Spider bites are normally painful to the touch, there is only a single bite mark, and they may result in a blister. Minor spider bites can be treated by washing the bite with soapy water, then applying a clean, cool cloth. Ice may be applied to reduce or prevent swelling. If at all possible, capture the spider that you suspect bit you. Contain it in a sealed container, such as a jar, and take it with you when seeking medical attention. This will help the doctor properly diagnose your injury and take the appropriate actions to counteract the venom.

• Since many spider bites are painless, it is not uncommon for the victim to have no idea of the type of spider that inflicted the wound. In some instances, the results of the bite can take 24 to 36 hours to appear. If the bite becomes painful to the touch, is oozing, develops dead tissue, or has red streaks radiating away from it, immediate medical attention should be sought. Additionally if the victim develops a fever, severe body pain, or vomiting, he should see a medical professional immediately.