Cellar spiders, with their remarkably long legs and small bodies, are a common sight in many homes. These arachnids are web-building spiders, generally considered harmless to humans and can even offer a degree of natural pest control within indoor environments.
The Unique Webs of Cellar Spiders
Cellar spiders construct webs that differ significantly from the neatly organized, spiral-shaped webs of other spider species. Their webs are loose, irregular, and three-dimensional. These structures are frequently found in corners of rooms, along ceilings, or in other undisturbed areas.
Unlike the sticky silk found in orb webs, cellar spider webs are not primarily designed for adhesion. Instead, their irregular, complex matrix of silk acts more like a tangled net, designed to ensnare and disorient prey. Over time, as these spiders continuously add new layers of silk without cleaning or consuming old sections, their webs can accumulate dust and debris, contributing to their characteristic “cobweb” appearance.
How Cellar Spiders Use Their Webs for Hunting
Cellar spiders use their unique webs for hunting. When prey, such as insects or other spiders, encounters the web, it becomes entangled in the loose silk. The cellar spider, often hanging upside down within its web, then uses its exceptionally long legs to quickly wrap the struggling victim in more silk, securing it from a safe distance. This method allows them to subdue prey much larger than themselves, including wolf spiders or black widows.
A distinctive behavior of cellar spiders is their “vibrating” or “shaking” of the web when disturbed or when prey is caught. This rapid pulsation further entangles prey, making escape difficult, or serves as a defense mechanism, blurring the spider’s outline. Their diet includes a range of small arthropods, such as mosquitoes, gnats, moths, flies, and other spiders. Cellar spiders have even been observed mimicking struggling prey in other spiders’ webs to lure and capture the web’s owner.
Identifying Cellar Spiders and Their Common Habitats
Cellar spiders have long, thin legs and a small, oval-shaped body. Their coloration ranges from pale yellowish to light brown or gray, offering effective camouflage. While sometimes called “daddy long-legs,” they are distinct from harvestmen, which lack silk glands and venom.
These spiders thrive in dark, damp, and undisturbed locations, frequently found in basements, cellars, crawl spaces, garages, and quiet corners of homes. In natural settings, they inhabit protected areas like cave openings and cliff crevices. Cellar spiders are beneficial, controlling insect populations and preying on other spiders, making them a natural form of pest management.