Common wasps are social insects and live in nests of up to around 10,000 workers. They build a paper nest in a hole in the ground. The paper is made by the wasps who chew small amounts of wood from trees, reeds or garden fences and mix it with saliva to form a pulp which is added to the nest in thin strips. The wasps do not construct their own burrow but will choose one which already exists such as an abandoned animal burrow, a garden shed, or the loft of a house. Workers forage and feed larvae, and cool the nest with water and fanning. Workers will aggressively defend the nest by stinging anything causing a disturbance. Unlike bees, wasps are able to sting repeatedly. The venom of the wasp contains a pheromone which acts as an alarm causing other wasps to become more aggressive when a wasp has stung something or has been killed. So it is a bad idea to swat a wasp near its nest site or to attempt to remove the nest yourself.