http://www.treknature.com/gallery/Europe/Belgium/Wallonia/Brabant_Wallon/photo143343.htm This small spider is a female Drapestica socialis (Family Linyphiidae) They can be found, often in numbers -hence their name I guess - on the bark of large trees in deciduous forests. They make a very small, almost invisible web on the surface and wait for crawling insects and other small spiders. The female is approx 4 mm long and the male smaller at 3 mm. Although they are far from rare, they are not often seen because their camouflage is much better than this sttrongly lighted image would make you think... This shot was taken in the Bois de Lauzelle, a protected area close to the University of Louvain