True to their namesake, jumping spiders can leap on their victims and kill them. This jumping ability is due to their keen eyesight. Jumping spiders are black and hairy. Females measure 0.3 inches to 0.75 inches long, and males are 0.25 inches to 0.6 inches long. They can have a small pattern of orange, yellow or white spots that can sometimes be seen on top of the abdomen. Male jumping spiders have what look like eyebrows, or small patches of hair, over their eyes.
Brown recluse spiders are some of the most dangerous spiders in northwestern Pennsylvania. The brown recluse is rare in the state but can occasionally be found in the wild. There are 11 species; only four are known to be harmless.
Cobweb weavers are also known as the common house spider. This spider is regularly seen in homes in Pennsylvania, mostly in places such as closets, corners of a room or hallway, crawl spaces and basements. Cobweb weavers are usually yellowish-brown with an abdomen that is creamy brown. The cobweb weaver breeds in a short time, and they tend to leave their current nest to start a new one. These spiders, though plentiful, are not a threat to humans.
Daddy longlegs are common in homes across the U.S., including in northwestern Pennsylvania. They are classified as longbodied cellar spiders and have extremely long legs. Females measure 0.3 inches long, and males are 0.25 inches long. The cylindrical abdomen is roughly three times as long as it is wide.
Grass spiders are commonly encountered in northwestern Pennsylvania. They are recognized by the large and somewhat concave and sheet-like web that they spin. This pattern is not encountered in the webs of many other spiders in the U.S. Grass spiders are marked by dorsal markings on the carapace and the abdomen. The carapace is yellow-brown to brown. Bites from grass spiders are not known to be dangerous to humans.
These spiders are commonly found in Pennsylvania as well as the rest of the U.S. They can be found in gardens, barns, tall weeds and generally sunny areas with bushes or some sort of supporting structure with which they can build their orb webs. They carry bright yellow patches on their abdomen. People are not likely to be bitten by these spiders, and they are not known to present a danger to people.
