Myth: Spiders are easy to identify

Illustration: Henry C. McCook
Illustration: Henry C. McCook

Myth: Spiders are easy to identify.

Fact: No such luck! Laypersons often assume that there are only a few spider species around, and all they'd need to identify them would be a few pictures. In reality, the world holds over 50,000 species of spiders classified into over 100 families. In your local area, there are likely at least 30 families and a few hundred species.

Even identifying a spider to family is no trivial task; all the many published keys to spider families are so organized that a beginner will go wrong about half the time. At species level, one needs an expensive microscope, a library of hundreds of separate books, monographs and articles, and a few years of experience to understand the many microscopic details that identify a spider, their similarities, differences, and variation.

Spider Myths

"Everything that 'everybody knows' about spiders is wrong!" —Rod Crawford sets the record straight with Spider Myths.

Telling spiders apart 

We tell families of spiders (114 worldwide, perhaps 30 in a given area) apart by characters like those below: eye arrangements, arrangement of trichobothria (special thin sensory hairs), spines, and the claws at the ends of the legs.

Eye arrangements

Front view of carapace of 5 genera and 5 families of North American spiders, showing eyes. Warning: these are only examples!There are many other 8-eyed arrangements; then there are the 6-eyed ones like the "recluse" group..

An illustration of spider eye arrangementsA close up view of a spider leg

End of leg of Cybaeus: trichobothria (arrows), spines, claws (at end).
Photo: Rod Crawford

close up of a spider

Spider Myth Resources

Explore even more! Additional spider resources and more myths (poor spiders can't catch a break!).

Photo: Cathy Morris/Burke Museum
Photo: Cathy Morris/Burke Museum