The presence of a wasp nest can be recognised by a steady stream of yellow and black-striped (ginger in the case of European hornet) insects flying to or from the nest entrance. Adult worker social wasps are about 15mm long but smaller individuals can occur, particularly in late spring. Queen wasps are larger and are 20-25mm long. Hornet workers can reach 25mm long and queens 30mm. Wasps are more slender and less hairy than bumblebees, which may also nest in the ground. Honeybees and most solitary bees are also hairier than wasps. Although nomad bees can appear superficially similar to wasps. There are also numerous species of solitary wasp in the UK, these solitary species can nest in close proximity to one another, but each female will have her own nest entrance. Solitary bees and wasps either have no sting or are very unlikely to sting. There are also many species of hoverfly that are wasp mimics.
Worker wasps feed the grubs in the nest on other invertebrates such as caterpillars and aphids. This activity can reduce pest problems in gardens in early summer. Later in the summer when wasp nests have passed their peak the demand for animal protein in the nest is lessened and wasps often to seek sugary substances.
Damage to plants is limited and mainly occurs in late summer, when social wasps can feed on ripe fruit. On tough-skinned fruits, such as apple, wasps enlarge cavities that have been initiated by other animals, such as bird pecks. On fruits with softer skins, such as grapes, plums and pear, wasps can initiate the damage.
Wasps can present a hazard if a wasp nest is disturbed. For example this can happen when compost bins are being emptied, hedges trimmed, rough grass is being mown or when flower beds are being weeded. Wasps will defend their nest by stinging anyone or animal who is nearby. If left alone wasps tend not to be aggressive. NHS Advice on stings
Worker wasps that are building the nest structure will gnaw wood fibres from wooden garden furniture, sheds and fences. This causes paler patches where the surface has been scraped off but no real damage is done.