The nests of some social wasps, such as hornets, are first constructed by the queen and reach about the size of a walnut before sterile female workers take over construction. The queen initially starts the nest by making a single layer or canopy and working outwards until she reaches the edges of the cavity. Beneath the canopy she constructs a stalk to which she can attach several cells; these cells are where the first eggs will be laid. The queen then continues to work outwards to the edges of the cavity after which she adds another tier. This process is repeated, each time adding a new tier until eventually enough female workers have been born and matured to take over construction of the nest leaving the queen to focus on reproduction. For this reason, the size of a nest is generally a good indicator of approximately how many female workers there are in the colony. Social wasp colonies often have populations exceeding several thousand female workers and at least one queen. Wasp nest treatment usually consists of the use of insecticide, this is often in the form of powder which is injected into and around the wasp nest entrance.

Hornets are the largest wasps found in the UK with some species reaching up to 5.5 cm (2.2 in) in length. The nest is founded in spring by a fertilized female known as the queen. It generally selects sheltered places like dark hollow tree trunks. It first builds a series of cells (up to 50) out of chewed tree bark. The cells are arranged in horizontal layers named combs, each cell being vertical and closed at the top. An egg is then laid in each cell. After 5–8 days, the egg hatches, and in the next two weeks, the larva undergoes its five stages. During this time, the queen feeds in a protein-rich diet of insects. Then, the larva spins a silk cap over the cell's opening and, during the next two weeks, transforms into an adult, a process called metamorphosis. Then, the adult eats its way through the silk cap. This first generation of workers, invariably females, will now gradually undertake all the tasks that were formerly carried out by the queen (foraging, nest building, taking care of the brood, etc.) with one exception: egg-laying, which remains exclusive to the queen. Hornet nest treatment usually consists of the use of insecticide, this is often in the form of powder which is injected into and around the hornet nest entrance.