In this video the spiny mason wasp Odynerus spinipes is seen, building the water-tap-like structure at its nest. Like shown in the video by the darker colour it moistens the material with collected water. For its nest it chooses protected and sunny walls of loam. Unfortunately these nesting sites have become rare and so has the spiny mason wasp which counts as endangered by now. To todays state of knowledge the noticeable water-tap-like structure is used as intermediate storage for building material for blockig the nest later on.