To identify a spider by region, look at its body shape, legs and eyes, note its activity and where it builds its web, and compare the findings to a taxonomic key or spider field guide to determine its type. Taxonomic keys and field guides usually contain information about the geographic range of spiders along with step-by-step methods to classify spiders. Alternatively, capture or kill the spider and take it to a county extension office for identification.
When identifying a spider, use a magnifying glass if necessary to examine the spider’s body shape, and note the length and shape of its legs. Spiders that build webs usually have long, slender legs, while jumping spiders have stocky, short legs and stout frames. If possible, examine the orientation and number of the spider's eyes for easier classification among spider families in the field guide or when using the taxonomic key.
The spider’s activity is also a clue to its type. Web-spinning spiders often stay in their webs, waiting for prey to happen along. By contrast, active hunting spiders such as wolf spiders move fast, often observed in the absence of webs. Keep in mind that even finding a spider in a specific region doesn’t mean it’s a native, since spiders from other locales often end up in other regions due to human transport.