a sap-run roughly an hour after dark and there may a ew of them in attendance at a single sap-run. They do not associate with each other, remaining well separated and do not move much when feeding. They will stay at the sap-run for much of the night, regularly detecting and preying on other insects that come to the sap-run. Their larvae grow within the nest detritus, eating other insects and, maybe, the dead and dying hornets too. As many 10 adult beetles and larvae may be found in a nest, and while they do not appear to prey on the hornets or their larvae, the nest must be occupied by hornets for the beetles to persist. References External links Velleius dilatatus (German) Staphylininae Beetles of Europe Beetles described in 1787 Taxa named by Johan Christian Fabricius