Barn Spider

The barn spider is a large, common orb weaver of eastern and central North America, well known both for its association with farm buildings and for being the species that inspired E. B. White's classic story Charlotte's Web. Its rounded, mottled brown-and-yellow abdomen provides effective camouflage against wood surfaces, allowing it to rest unnoticed near the barns, sheds, porches, and bridges where it commonly builds its web.

Like other members of the genus Araneus, the barn spider spins a large, symmetrical wheel-shaped web each night, typically near a light source or structure that attracts flying insects, and takes the web down each morning to conserve silk. Females are considerably larger and more visible than males and become especially conspicuous in late summer as they reach full size.

Barn spiders are beneficial predators that help control flying insect populations around the structures they inhabit, and their large size combined with docile temperament has made them a familiar and generally tolerated sight in rural and semi-rural areas.

• Rounded, mottled abdomen in shades of brown, tan, and yellow, often with a pattern resembling a leaf or splash
• Legs banded with alternating light and dark segments
• Females significantly larger and rounder than the smaller, slimmer males
• Builds a large, vertical orb web, often near barns, porches, or bridges, typically rebuilt each night
• Similar in appearance to other Araneus orb weavers, distinguished mainly by habitat association and specific mottled pattern

Barn spiders are strongly associated with human structures such as barns, sheds, porches, and bridges, as well as natural sites like cave entrances and rock overhangs, across the eastern and central United States and adjacent Canada. They favor sites near artificial or natural light sources that attract night-flying insects. Adults are most active and visible from mid-summer through fall.

This nocturnal spider constructs a fresh orb web each evening, often near lights that draw moths and other flying insects, then dismantles and consumes much of the silk each morning before retreating to a nearby hiding spot for the day. Diet consists primarily of flying insects intercepted in the web's sticky spiral. Barn spiders are solitary and non-aggressive, relying on camouflage and retreat rather than defense when disturbed, and serve as effective natural control for night-flying insect populations around the structures they inhabit.

Females lay eggs in a protected silk sac in late fall, often tucked into a crevice near their web site, and the adults typically die with the onset of cold weather. Eggs overwinter and hatch in spring, with spiderlings dispersing to establish their own web sites and growing through repeated molts over the summer. The species completes one generation annually, with adults reaching peak size and mating activity in late summer and early fall.