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Are spider bites common? When my mother finds an itchy bump on my skin, she often claims it is a spider bite. But my father says that spiders don't bite people very often and it must be something else. Thank you
Question Date: 2005-11-22
Answer 1:

Great question!!! The short answer is, spiders bite, of course, but not as often as we think they do. So, your father is right!

A spider researcher (called an "arachnologist" by the way) named Darwin Vest once conducted a study to answer that very same question. He asked a whole bunch of doctors to tell him how often they saw patience that came to their office with a "spider bite" or at least what they thought was a spider bite. Then, he asked them how often these bites were actually made by spiders. The result: over 80% of the bites that people thought were caused by spiders were in fact caused by insects - not spiders! In other words, spiders get a bad rap. They don't bite people as often as we think they do. So, how do doctors know whether it's a spider bite or an insect bite? Have you ever looked carefully into the face of a spider? If you do, you might notice that they have two fangs hanging down from their cephalothorax (or "head" area). When spiders bite they thrust these fangs into their prey (or, your skin) and they create two holes. Insects typically have a "stinger" of some kind that creates only one hole. So, if you look at a bite and you can see two, tiny holes, it's probably a spider bite.

More likely, however, you'll see one hole and therefore it's an insect "bite."But beware! If it is, in fact, a spider bite, you should keep a close eye on it and monitor how you're feeling. Some spider bites can be very, very bad.

For example, around here, the brown recluse and the black widow make painful and sometimes fatal bites! If you have any question about whether it's a spider bite or an insect bite and you're worried about it, see a doctor right away. Better safe than sorry. :)

Answer 2:

I read that spiders are not very aggressive and usually only bite humans when they are trapped close to the skin inside bed sheets or clothes.If the bumps are on your chest or upper legs, they might be spider bites that happened when a spider got trapped in your clothes. If the bumps are on your lower legs or arms, though, maybe your dad is right and they are something else.

Answer 3:

Scientists probably don't know exactly how common bites are from various different kinds of spiders. In general, though, I agree with your father--spider bites are not that common. Bites from other animals, like insects, are probably much more common.

There are a large number of lice, mites, fleas, mosquitoes, and many other kinds of bugs in our environment that occasionally bite people, and some people have stronger reactions to them than others people do. So there might be some kind of mite that bites everyone in your family, but only your mother gets itchy bumps from the bites!

Answer 4:

Spider bites happen, and they're certainly not rare. There are a large number of insects that bite, too, mostly flies of various sorts (e.g. mosquitoes). Spider bites are for the most part bigger and itchier than mosquito bites, though, since what spiders inject is more obnoxious stuff than what flies do (i.e. venom that is actually poisonous, instead of just saliva to which you have an allergic reaction). Wasps (including bees) also inject venom, but you normally know about it right away when a wasp stings you.

Answer 5:

It can be hard to tell what type of insect or spider bites us, because we often do not notice until later when the bites become itchy (except mosquitoes -- they are very noticeable at the time). Many people say that itchy bumps are from "spider bites" when they might actually be from fleas, ticks, mites, bedbugs, flies, or ants. Spiders do not usually travel in groups and they do not tend to bite more than once. So, if you have a group of small red bumps, they are probably from fleas or mites. If you have just one bite, perhaps it could be a spider. However, overall spiders are much more useful than dangerous (except maybe black widows). Spiders can eat 2000 insects per year! Think of how many less insect bites we get because of spiders.

When I was a child and I came home covered in small red bites, sometimes my mother took me to the doctor. The doctor would look at me and say it was O.G.K. -- which he said stood for Only God Knows. Even he could not tell exactly what was biting me. All the best.

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