Nests are commonly built in rodent burrows, but other protected cavities, like voids in walls and ceilings of houses, sometimes are selected as nesting sites. Colonies, which are begun each spring by a single reproductive female, can reach populations of between 1,500 and 15,000 individuals, depending on the species.
The wasps build a nest of paper made from fibers scraped from wood mixed with saliva. It is built as multiple tiers of vertical cells, similar to nests of paper wasps, but enclosed by a paper envelope around the outside that usually contains a single entrance hole.
If the rodent hole is not spacious enough, yellow-jackets will increase the size by moistening the soil and digging.Similar behavior inside a house sometimes leads to a wet patch that develops into a hole in a wall or ceiling.
Aerial-nesting yellowjackets, Dolichovespula arenaria and D. maculata, build paper nests that are attached to the eaves of a building or are hanging from the limb of a tree.The entrance is normally a hole at the bottom of the nest.
These aerial nesters do not become scavengers at the end of the season, but they are extremely defensive when their nests are disturbed. Defending D. arenaria sometimes bite and/or sting, simultaneously.
Wasp stingers have no barbs and can be used repeatedly, especially when the wasp gets inside clothing. As with any stinging incident, it is best to leave the area of the nest site as quickly as possible if wasps start stinging.
Wasps may live solitary in ground holes, clay pots, or bamboo stem cavities. Species that cause nuisance, however, are social insects and live in papery nests hanging from trees or building surfaces. The most commonly found species are: (a) Vespa bicolor (b) Vespa affinis (c) Polistes olivaceous
They may fly 2-3 km to search for food. Large aggregation of wasps is usually caused by food attraction.
Scavenging wasps will not usually become a problem if there is no food around to attract them. When nuisance wasps are present in the outdoor environment, keep foods (including pet food) and drinks covered or inside the house and keep garbage in tightly sealed garbage cans.
Once food is discovered by wasps, they will continue to hunt around that location long after the source has been removed.
Most social wasps provide an extremely beneficial service by eliminating large numbers of other pest insects through predation and should be protected and encouraged to nest in areas of little human or animal activity.
The best way to prevent unpleasant encounters with social wasps is to avoid them. If you know where they are, try not to go near their nesting places.
Wasps can become very defensive when their nest is disturbed. Be on the lookout for nests when outdoors. Wasps that are flying directly in and out of a single location are probably flying to and from their nest.