The web of pholcids has no adhesive properties and instead relies on its irregular structure to trap prey. Behavior Cellar spider vibrating rapidly in response to a threat Trapping In areas of human habitation pholcids construct webs in undisturbed areas in buildings such as high corners, attics and cellars, hence the common name 'cellar spider'. These webs are constructed in dark and damp recesses such as in caves, under rocks and loose bark, and in abandoned mammal burrows. Pholcids hang inverted in their messy and irregular-shaped webs. Pholcids are found in every continent in the world except Antarctica. They can be further distinguished by their irregular structure, and usually brown, tan or grey coloration. But they can be easily differentiated by the two segments, that members of this family have, while harvestmen have fused segments. These spiders have legs roughly 4 times as large as their bodies, making them look quite a lot like harvestmen ( Opiliones).

Pholcids are gray to brown, sometimes clear, with banding or chevron markings. Spermophora has a small globose abdomen and its eyes are arranged in two groups of three without median eyes. Arrangements of eight and six eyes both occur in this family. Pholcus and Smeringopus have cylindrical abdomens and eyes arranged in two lateral groups of three and two smaller median contiguous eyes. The body, resembling the shape of a peanut, is approximately 2–10 mm (0.08–0.39 inch) in length, and the legs may be up to 50 mm (1.97 inches) long. Pholcids are thin and delicate arachnids. The common name 'daddy long-legs' is used for several species, especially Pholcus phalangioides, but is also the common name for several other arthropod groups, including harvestmen and crane flies.

The family, first described by Carl Ludwig Koch in 1850, is divided into 94 genera. The family contains more than 1,800 individual species of pholcids, including those commonly known as cellar spider, daddy long-legs spider, carpenter spider, daddy long-legger, vibrating spider, gyrating spider, long daddy, and skull spider. The Pholcidae are a family of araneomorph spiders. Close-up of a cellar spider's cephalothorax, showing two groups of three clustered eyes

Long bodied cellar spider bite humans