The creatures themselves resemble their cousins the wasps in shape and to some extent colour. One clear difference is that wasps typically are yellow and black whereas hornets are yellow and chestnut brown. The most obvious difference however is that hornets are around double the size of your average wasp. Hornets can be up to about 3.5cm in size (that’s roughly the length of your little finger from the middle knuckle to the end of your nail).
Hornets like wooded areas because they need old, semi-rotten trees which they harvest soft wood from and chew up into a paper mache-like substance they use to build their nests. These nests often turn up in buildings or in bird nest boxes as circular structures with multiple, hexagon-shaped larval holes tucked away in the core. The structures themselves are incredibly delicate and can be crushed quite easily between thumb and forefinger.
You are most likely to see hornets on the wing in mid to late summer as they emerge from their nests on hunting missions. Adult hornets will feast on sap and honeydew and nectar, all of which are high in energy and readily available in the summer months. Whilst feeding, hornets also provide a valuable service in pollinating woodland trees and plants where other pollinators are often fewer in number or absent. Many later flowering woodland edge plants such as foxgloves and helleborines have large flowers to attract large bodied insects such as hornets and bees.
Hornets also play an active role in controlling invertebrates and keeping numbers down – hunting beetles and moths and even have a taste for wasps. They capture these insects to feed the larvae in the nest as a protein-rich food source.
Hornets will be flying throughout the summer and can even be spotted on warm days into November, feasting on fallen fruit before next year’s queens start to hibernate in crevices and sheltered places.
Given their size and their similarity to troublesome wasps, hornets often carry a reputation that they haven’t really earned. They are generally placid creatures that are really unlikely to sting – though disturbing an active nest might be best avoided. There’s also no truth in the old folk tales that it only takes the sting of three hornets to kill an adult.
Look out for hornets busily looking for food sources along wide clearings and glades at our wooded nature reserves at Weston Big Wood, Browne’s Folly and Priors Wood.
Find out more about these nature reserves and how to get there.