Non-web-building-spider
Guides
Castianeira cingulata
twobanded antmimic, two-banded ant-mimic sac spider
Castianeira cingulata is a small ant-mimicking spider in the family Corinnidae, commonly known as the twobanded antmimic. Females measure 7–8 mm in body length, males 6–7 mm. The species exhibits Batesian mimicry of carpenter ants through coloration, body shape, and behavioral displays including bobbing movements and foreleg waving that simulates antennae. It inhabits woodland leaf litter across eastern North America, where it hunts insect prey.
ant-mimicryBatesian-mimicryleaf-litter-predatorCorinnidaeeastern-North-Americaforest-floor-spiderharmless-to-humansoverwintering-in-silk-sacksdiurnal-and-nocturnalslow-deliberate-movementforeleg-waving-displaysmall-size-6-8mmtwo-pale-abdominal-bandscarpenter-ant-mimicwoodland-habitatactive-hunternon-web-building-spidersilken-retreat-constructionpotential-multi-year-lifespan-in-southwandering-behavior-brings-indoorsClubiona pacifica
Pacific sac spider
Clubiona pacifica is a species of sac spider in the family Clubionidae, first described by Banks in 1896. It is found in the United States and Canada, with confirmed records from Alberta and British Columbia. As a sac spider, it does not construct webs for prey capture but instead actively hunts. The species has been the subject of life history and ecological studies in Washington State.
Clubiona spiralis
sac spider
Clubiona spiralis is a species of sac spider in the family Clubionidae, first described by Emerton in 1909. It occurs in the United States and Canada. Like other members of its genus, it is an active hunter that does not build webs for prey capture.
Drassodes neglectus
Neglected Ground Hunter Spider
Drassodes neglectus is a ground spider in the family Gnaphosidae, characterized by its ground-dwelling hunting behavior. The species occurs across a broad geographic range spanning Russia (Far East, Middle to East Siberia), Kazakhstan, and North America. It belongs to a genus of active hunters that do not construct webs for prey capture. Available records indicate it has been documented in 35 iNaturalist observations.
Thomisidae
crab spiders, flower spiders, flower crab spiders
Thomisidae is a large family of spiders comprising approximately 172 genera and over 2,100 species worldwide. Members are commonly called crab spiders or flower spiders due to their laterigrade leg orientation—legs twisted at the base to project horizontally—enabling sideways and backward movement reminiscent of true crabs. These spiders are ambush predators that do not construct prey-capture webs, instead relying on stealth, camouflage, and rapid leg strikes to subdue prey. Many species exhibit remarkable color change abilities to match floral backgrounds, while others mimic bird droppings or hunt in leaf litter and bark crevices.
Tibellus duttoni
Dutton's Slender Crab Spider
Tibellus duttoni is a running crab spider in the family Philodromidae, characterized by its elongated body form and grass-mimicking appearance. It hunts by ambush on vegetation rather than building webs to capture prey. The species occurs across much of North America, including the United States, Mexico, and southern Canada. Adults are relatively small, with females typically larger than males.