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Spiders, like other insects, have the ability to bite. Rather than teeth, spiders have hollow fangs containing varying degrees of potent venom, which they instinctively use to kill their natural prey – mostly other insects. These bites on humans can occur when a human comes unknowingly into contact with certain spiders.
Since all spiders have the ability to bite, many people mistakenly assume any spider can bite them. However, most spiders’ fangs either too small or too delicate to break human skin. There are some exceptions, thus making spider bites a potential cause for concern.
Bites can occur from contact with numerous species and in many cases are classified as dry bites, or a bite when the spider is merely being defensive and injects no venom. Most bites are not harmful to humans and typical reactions are similar to other insect bites, including a small red or swollen bump accompanied by irritation or itching. Many people do not feel the bite and may not even notice a reaction. In rare cases, people may experience a more severe allergic reaction to a spider bite.
While the majority of spider bites are not harmful to humans, there are a few spiders throughout the world whose bites are considered dangerous. These spiders include the black widow, the recluse, the Brazilian wandering spider, funnel web spider, certain species of tarantulas, and sand spiders indigenous to parts of Africa. Those spiders with neurotoxic venom, including the widow, funnel-web, and wandering spiders are considered to pose the greatest threat, though there have been deaths reported with spiders containing both neurotoxic and necrotic venom.
Treatment for the majority of these bites is not all that different from other insect bites and includes thorough washing of the area to prevent infection, a cool compress to relieve pain and swelling, as well as the application of a topical analgesic. In the case of a venomous bite, swelling and redness may be accompanied by adverse reactions, such as muscle pain and immobility, severe swelling, fever, nausea, and death of surrounding tissue.
The majority of spider bites are insignificant and do not require medical attention. However, bites from spiders known to be potentially harmful to humans should receive immediate medical attention. There is anti-venom available to counteract neurotoxic venom from bites of known species, but it is important that the victim know what type of spider has bitten him or her. The potential for a serious or lethal reaction is greater in children and those people who may actually suffer from an allergy to specific venom.
Though the potential for harmful spider bites is slim, it is important to be cognizant of those spiders indigenous to your area that are considered dangerous and to be able to identify them. Keep in mind that spiders typically administer a single bite, not multiple bites, so if you find small, red and swollen bumps that are causing dermatological problems, your home may be infested with fleas, mites, or bedbugs rather than spiders.