English: Nest of stingless bees Trigona spinipes on the wall of a building at the State University of Campinas, Brazil. The nest is a couple of months old; it is built of dirt and other debris. The greenish part (possibly including cow or horse dung) is the most recent addition. A couple of bees are visible as bright specks. The cinder blocks are about 40 cm wide and 19 cm tall excluding the mortar. The wall is painted tan-beige; the white smudges below the nest are places where the paint peeled off showing the older white paint layer. Picture taken by J. Stolfi with a Sony DSC-V1 camera, with some post-processing.