A spider’s diet consists primarily of living insects, or sometimes, other spiders. One way to categorize spiders is by how they hunt their prey. We can divide spiders by their hunting techniques into those that build webs ("web-building" spiders) and those that rely on active hunting ("wandering" spiders). These two categories can be further divided, either by the type of web a spider builds (for example, orb-web versus cobweb), or by the strategy it employs when actively hunting (for example, ambushing versus stalking).

This website groups spiders first by where one might find them, and then by their hunting technique.

Spiders Commonly Found in Houses in Portland, OR

Spiders Commonly Found in Yards and Gardens in Portland, OR

Common Misconceptions About Spiders

Mention the word “spider” and many people react with fear. Fortunately, though, there is little to fear.

Can spiders bite people?
Spiders’ mouthparts are adapted for feeding on small insects — and not large animals such as dogs, cats, and people. Many spiders could not even bite a person if they tried, as their tiny chelicerae cannot open widely enough to pinch into human skin. Try to open your mouth wide enough to bite into a wall. This gives you an idea of how ineffective many spiders would be if they tried to bite into something as large as a person. However, some spiders can open their chelicerae wide enough to bite a person, cat, or dog. Which leads to the next question……

Do spiders bite people?
Let’s look at this from a spider’s perspective. It goes about its business of seeking a meal, and its diet consists of insects and other arthropods. It can feed only on liquids, so it needs to liquefy its insect prey before it can eat them. Since it cannot do this to large animals, it would be a complete waste of its time to even try.

Can insects bite people?
YES! Unlike spiders, many insects are capable of feeding on large animals, such as people. Fleas, bed bugs, and mosquitoes all have mouthparts adapted to feeding on animals such as dogs, cats, and people.

Do insects bite people?
YES! Some insects such as mosquitoes, fleas, and bed bugs must feed on animals other than arthropods. Furthermore, unlike spiders, many insects carry diseases harmful to the animals they feed on. For example, certain mosquitoes spread malaria, a leading cause of human disease. While bed bugs are not known to carry human diseases, their bites often cause allergic reactions. Bed bugs are proliferating in many U.S. cities, and many dwellings in Portland are infested with bed bugs. These animals hide during the day, and come out at night to feed on people, cats, and dogs, so you may have little idea that they reside in your home. For more information about bed bugs, see the website http://en.wikipedia.org/wiki/Bedbug

So the next time you think you’ve been bitten by a spider, consider all the more likely options first!

Links to other spider related webpages:

American Arachnological Society

European Society of Arachnology

Australasian Arachnological Society

International Sociey for Arachnology

The "Spider Myths Web Site"