The spitting spider (Scytodes) is an arachnid whose name often triggers alarm, but its reputation is unwarranted. This spider is famous for its unusual hunting method, which involves shooting a sticky substance at its prey rather than using a traditional web. Despite this unique behavior, the spitting spider poses no medical danger to people. Their interaction with humans is rare and entirely non-threatening, making them one of the most harmless spiders found in residential areas.
Identification and Common Habitats
The common spitting spider (Scytodes thoracica) is a small, delicate arachnid, typically 3 to 6 millimeters long. Its most noticeable feature is a large, dome-shaped cephalothorax, which houses the specialized glands used for its unique hunting strategy. The spider often exhibits a pale yellow or cream coloration, frequently marked with dark speckles or patterns.
A key difference from most other spiders is that the spitting spider possesses only six eyes, arranged in three pairs, instead of the usual eight. This cosmopolitan species is found across the globe, including Europe, North America, and parts of Asia. Spitting spiders are nocturnal hunters that seek warm, sheltered environments, often hiding in dark crevices, closets, cellars, and behind furniture inside homes.
Assessing the Threat to Humans
The spitting spider presents a minimal health risk to humans. The spider is non-aggressive and prefers to retreat when disturbed, only biting in self-defense if trapped or squeezed. Even in the rare event of a bite, the spider’s fangs are diminutive and often too small to effectively pierce human skin.
The venom is highly specific, designed to quickly paralyze and subdue insect prey, not mammals. If a bite were to occur, symptoms would be mild and localized, typically involving slight, temporary discomfort. The venom is not medically significant, and bites do not require professional medical treatment.
The Unique Hunting Mechanism
The mechanism that gives the spitting spider its name sets it apart from other arachnids. Unlike web-building spiders, Scytodes actively hunts, using its dome-shaped cephalothorax to house a pair of large glands. These glands produce a mixture of silk, glue, and venom that is propelled at the target.
When hunting, the spider sneaks close to its prey, such as a silverfish or moth, and rapidly oscillates its fangs to eject the sticky substance. The mixture is shot out of the fangs in two separate streams that cross, creating a powerful, zigzagging net of adhesive silk. This rapid-fire action happens in a fraction of a second, sometimes as fast as 1/600th of a second, instantly immobilizing the prey against the surface.
Management and Prevention
The presence of spitting spiders often indicates a thriving population of other small insects, as the spiders are following their food source. Since these spiders are beneficial natural pest controllers, unnecessary chemical treatments are discouraged. The most effective management strategy focuses on exclusion and habitat disruption.
Sealing small cracks and crevices in foundations, windows, and doors will reduce the number of entry points for both the spiders and their prey. Indoors, spiders seek out clutter for hiding, so reducing piles of boxes or debris in areas like basements and closets removes their preferred habitat. Regular cleaning and vacuuming of dark corners and baseboards will help remove the spiders, their webs, and any potential egg sacs.