Some wasp species are eusocial which means they live together in a nest with an egg-laying queen and non-reproducing workers. However, the majority of wasp species are solitary, with each adult female living and breeding independently. Many of the solitary wasps are parasitoidal, meaning that they raise their young by laying eggs on or in other insects. The wasp larvae eventually kill their hosts.

Depneding on the species of wasps, they feed on different types of food including other insects, fallen fruit, nectar, and carrion such as dead insects.

Social wasps are considered pests when they become excessively common, or nest close to buildings. People are most often stung in late summer, when wasp colonies stop breeding new workers; the existing workers search for sugary foods and are more likely to come into contact with humans; if people then respond aggressively, the wasps sting. Wasp nests made in or near houses, such as in roof spaces, can present a danger as the wasps may sting if people come close to them. Stings are usually painful rather than dangerous, but in rare cases people may suffer life-threatening anaphylactic shock.