Spitting spiders (family Scytodidae) are arachnids known for their unusual hunting method. Unlike many spiders that use webs, these creatures employ a distinct strategy involving a specialized “spit.” This adaptation raises questions about their behavior and potential interactions with humans.
Understanding Spitting Spiders
Spitting spiders are small arachnids, typically measuring 3 to 6 millimeters in body length. They have a pale yellow to light brown body, often with dark spots or patterns. A distinguishing feature is their dome-shaped cephalothorax, which is large to accommodate specialized glands. They also possess long, slender legs with dark bands.
Globally distributed, spitting spiders are found in various habitats, including houses, under rocks, and in leaf litter. Unlike most spiders, they typically have only six eyes, arranged in three pairs. This six-eyed arrangement and their unique body shape can sometimes lead to misidentification with other spiders, such as the brown recluse. However, their specific leg and body patterns aid in identification.
How Spitting Spiders Attack
Spitting spiders use a unique hunting technique, diverging from traditional web-spinning. They actively stalk victims instead of constructing passive webs. Once in range (typically 10 to 20 millimeters), the spider ejects a sticky, venomous silk substance from its chelicerae. This “spit” combines liquid silk and venom, stored in enlarged glands within their dome-shaped cephalothorax.
The spider rapidly moves its fangs, forming two zigzagging strands that create a strong net. This attack sequence occurs extremely fast. Upon contact, the venom-laced silk rapidly congeals, immobilizing the prey. Their prey typically includes small insects and other arthropods like silverfish, moths, and flies. After ensnaring and paralyzing the prey, the spider injects digestive saliva, liquefying the insides before consumption.
Are Spitting Spiders Dangerous to Humans
Despite their unique hunting method, spitting spiders are not considered dangerous to humans. While their “spit” contains venom, it is adapted for subduing small insect prey. This venom has very low potency against larger organisms, including humans. Any effects on humans are negligible, similar to a minor insect bite.
Their fangs are also quite small, making it difficult to penetrate human skin. Spitting spiders are timid, preferring to flee rather than bite defensively. Bites are rare, typically occurring only if the spider feels threatened or is accidentally pressed against the skin. Even then, any symptoms would be mild and localized, requiring little medical treatment.
What to Do If You See a Spitting Spider
Encountering a spitting spider in your home or garden generally requires no intervention. Given their harmless nature, simply leave them undisturbed. These spiders are not aggressive and pose no threat. They are beneficial, preying on common household pests like silverfish, moths, and flies.
If a spitting spider is found indoors and causes concern, it can be gently relocated outside. Use a cup and paper to scoop the spider, a safe method for moving it without harm. Their non-aggressive behavior means they are unlikely to bite during relocation.