Comb-footed Spider

Comb-footed spiders make up the family Theridiidae, one of the largest and most widespread spider families, with thousands of described species occupying nearly every terrestrial habitat around the globe. The family name refers to a specialized anatomical feature found on the hind pair of legs: a row of small, curved, serrated bristles called a comb, located on the tarsus.

This leg comb gives the group its defining hunting technique. When prey becomes caught in the irregular, tangled web typical of the family, the spider uses its combed hind legs to rapidly draw out silk from its spinnerets and fling it over the struggling animal, wrapping it far more quickly than would be possible by touch alone. This efficient wrapping method allows comb-footed spiders to subdue prey that might otherwise be too large or dangerous to approach directly.

The family includes an enormous range of body forms and habits, from tiny inconspicuous garden spiders to the more robust and well-known widow spiders, all of which share the tangled cobweb architecture and the distinctive leg comb that unites the group taxonomically.

• Rounded, often bulbous abdomen, with enormous variation in color and pattern across species
• Row of small, serrated, comb-like bristles on the tarsus of the hind legs, visible under magnification
• Web is an irregular, tangled, three-dimensional mesh rather than a flat spiral
• Sticky gumfoot lines often run from the web down to the ground to snag walking prey
• Relatively short legs suited to maneuvering through a dense silk tangle
• Lookalikes include other tangle-web spiders, but the hind-leg comb is the definitive family trait confirmed under magnification

Comb-footed spiders are found in virtually every terrestrial habitat worldwide, from forests and grasslands to deserts and urban structures. They build their tangled webs in sheltered locations such as foliage, bark crevices, rock piles, and building corners, and are present year-round in warm climates, with seasonal activity peaks in temperate regions during the warmer months.

These spiders rely on their irregular tangle web and, in many species, sticky gumfoot threads to intercept walking or flying prey. Once an insect is snagged, the spider uses its combed hind legs to swiftly fling silk over it, immobilizing the prey before delivering a subduing bite and beginning to feed. Diet varies by species but generally includes flies, ants, beetles, and other small arthropods. Given the sheer diversity and abundance of the family, comb-footed spiders are significant predators of small insects in nearly every ecosystem they inhabit.

Females produce one or more silk egg sacs, often spherical or teardrop-shaped, suspended within the web and guarded until the spiderlings emerge. After hatching, young spiders disperse to build their own tangled webs nearby, growing through repeated molts over several months to about a year depending on the species and climate. Many temperate species overwinter as eggs or juveniles, resuming growth and web-building as temperatures rise.