The brown recluse spider, Loxosceles reclusa, often prompts concern, and its presence is frequently first noted by the silk it produces. Unlike many spiders that rely on spun silk for trapping prey, the brown recluse constructs a web for a distinctly different purpose. The web serves not as a hunting snare but primarily as a retreat, providing a safe, hidden sanctuary. Understanding the unique structure and location of these retreats is the most reliable way to identify potential recluse activity.
Physical Characteristics of Recluse Webs
The web of a brown recluse spider is irregular and chaotic, lacking the structured symmetry seen in common spider webs. It is composed of a loose network of disorderly silk strands, creating a messy appearance. This structure is often flat and small, built close to a supporting surface.
The silk is typically a dull, grayish-white or off-white color, helping it blend into the dusty, dark environments where the spider resides. The finished web can resemble a small, tangled sheet or cottony debris. It does not feature the distinct radial spokes or spiral patterns of an orb weaver’s construction.
These retreats are fragile shelters, not meant to withstand the impact of flying insects or hold struggling prey. They allow the nocturnal spider to rest undisturbed during daylight hours. Females also use this silk to construct small, protective egg sacs within the shelter.
Typical Web Placement and Function
The primary function of the brown recluse web is to serve as a retreat, which is why it is almost exclusively found in secluded locations. The spider is a nocturnal hunter, leaving the protection of its web at night to actively seek out small insects for food. The web is simply a secure place to hide.
These webs are typically constructed in dry, dark, and undisturbed areas where the spider can remain concealed. Common indoor locations include basements, attics, crawlspaces, and rarely accessed closets.
They frequently spin retreats inside storage boxes, beneath undisturbed furniture, behind baseboards, and within piles of clothing or linens. The spider shows a preference for cardboard, mimicking the rotting tree bark it inhabits outdoors. Outdoors, retreats are found under woodpiles, rocks, logs, sheds, and garages.
Distinguishing Recluse Webs from Other Spiders
Differentiating a brown recluse web from those of other common house spiders involves observing both the structure and the placement. Large, symmetrical orb webs, often suspended between trees or window frames, are constructed by garden spiders to actively intercept flying insects. These orb webs are visually distinct and built for hunting, a function the recluse web does not serve.
Another common web is the three-dimensional, messy cobweb, frequently spun by house spiders or cellar spiders. While these cobwebs are irregular and chaotic, they are often much larger than recluse retreats and placed high up in corners of rooms or ceilings to catch flying prey. In contrast, the brown recluse retreat is small, flatter, and usually positioned very close to the floor or a supporting surface.