Sac spider

The sac spiders of the family Clubionidae are nocturnal, sac-building hunting spiders with a near-worldwide distribution. Their sacs, silken retreats in which they hide during the day, may be made in a variety of places, including between folded leaves or grass blades, under bark and below rocks or other ground litter.

Although formerly a much larger catch-all taxon, in its current definition the family contains less than 700 described species across 18 genera, of which Clubiona is by far most species-rich, with 528 accepted species as of November 2024.