Scanning electron micrograph (SEM) of Riparin sac spider spiderling (Clubiona riparia), Clubionidae family. Sac spiders from this family, also known as clubionoids are one of a group of non-web-making spiders. Clubiona riparia uses the tip of a leaf for both a nursery and a coffin. The female sac spider folds down the leaf tip to make an enclosure fastened and lined with silk to deposit its egg sac and then remains until the spiderings feed on her body. The clubionoids have eight eyes arranged in two rows and conical anterior spinnerets. They are wandering predators that build silken retreats, or sacs, usually on plant terminals, between leaves, under bark or under rocks. Sac spiders are important predators that feed on insects and insect eggs that are agricultural pests. They are nocturnal hunters. Magnification: x18 when shortest axis printed at 25 millimetres.