North Carolina’s diverse geography, ranging from the coast to the mountains, supports a rich array of arachnids. The state is home to hundreds of spider species, most of which are harmless to humans and play a beneficial role in controlling insect populations. Understanding the common species encountered in and around homes helps distinguish between nuisance spiders and the few that warrant caution. This knowledge promotes a balanced perspective on these common residents.
The Most Common Household Spiders
Most spiders encountered indoors are non-aggressive and prefer undisturbed areas. Cellar spiders, often called “daddy long-legs,” are common in basements, crawl spaces, and dark corners. They have small, pale bodies and disproportionately long, thin legs that can span up to two inches. They weave loose, irregular webs in damp environments and are considered beneficial because they sometimes prey on other spiders, including black widows.
Wolf spiders are active hunters that do not spin webs to catch prey. These robust, hairy spiders are often mistaken for the brown recluse due to their size, reaching up to two inches in leg span. They are brown or gray with distinctive markings and are commonly found running along floors or under furniture, having entered structures accidentally from outdoor habitats.
Common house spiders, which are cobweb spiders, build the messy, irregular webs often seen in corners or under eaves. These small, brownish spiders are timid, and their rare bites result in only minor, localized irritation.
Spiders That Cause Concern
Only a small number of spiders in North Carolina are medically significant, with the black widow being the most prevalent species. The adult female black widow is identified by her glossy black body and the distinct red or orange hourglass marking on the underside of her abdomen. They prefer to build their irregular, strong webs in dark, protected areas, such as woodpiles, cluttered basements, sheds, and under outdoor furniture.
A bite from a female black widow injects neurotoxic venom, which affects the nervous system. Symptoms can include severe muscle cramps, abdominal pain, nausea, and elevated blood pressure. While the bite may feel like a pinprick, symptoms develop over several hours, making prompt medical attention necessary, especially for children or the elderly. Black widows are non-aggressive and only bite if they feel threatened, often when accidentally pressed against skin or clothing.
The brown recluse spider is the second species that can cause medical concern, though its status in North Carolina is often exaggerated. It is characterized by a violin-shaped marking on its cephalothorax, with the “neck” pointing toward the abdomen. It possesses six eyes arranged in three pairs, distinguishing it from most other spiders which have eight eyes. The venom is necrotic, meaning it can cause tissue damage around the bite site.
The brown recluse is extremely rare in most of North Carolina, with established populations limited to the westernmost edge of the state. Most suspected sightings or bites are misidentifications of other common, harmless spiders. When found, these spiders prefer dry, undisturbed environments like attics, seldom-used closets, and inside storage boxes, rarely venturing into open living spaces.
Iconic Outdoor Web Builders
The largest spiders in North Carolina are known for their striking appearance and elaborate webs. The black and yellow garden spider, or writing spider, is highly recognizable due to the female’s bright yellow and black markings. These large orb weavers construct massive, intricate, wheel-shaped webs, often including a dense, zigzag pattern of silk called a stabilimentum.
These spiders are found in gardens and tall vegetation, positioning their webs to catch flying insects. Despite their size, they are docile and pose no threat to humans. Other orb weavers, such as the Golden Silk Orbweaver, also build large, circular webs and exhibit a bright yellow coloration. Their impressive web structures are a common sight and help control outdoor insect populations.