Wood ant

How they shape the landscape

Wood ants are true ecosystem engineers. Their huge nest mounds tunnel deep into the ground. By building these nests, wood ants help turn and aerate the soil. To regulate nest temperature and humidity, wood ants gather pine needles, twigs and dried grass. This activity enriches the soil with organic material, improving its fertility and quality.

Ants have a fascinating symbiotic relationship with aphids, which feed on tree sap and excrete a sugary substance called honeydew. The omnivorous ants feed on this honeydew and ​‘farm’ the aphids by moving them to optimal spots and protecting them from predators. Ants are aggressive predators and help regulate insect populations which benefit tree health. Additionally, wood ants play a key role in seed dispersal. Some plants even produce seeds with a sugary coating to attract them.

Wood ants serve as prey for species higher up the food chain, such as badgers, pine martens and birds. In addition to being a food source for birds, wood ants unintentionally help birds get rid of ectoparasites by spraying formic acid on their feathers when disturbed, which acts as an insecticide.

Where they like to be

In Britain, there are four wood ant species: the southern or red wood ant (Formica rufa), the Scottish wood ant (F. aquilonia), the hairy wood ant (F. lugubris) and the European red wood ant (F. pratensis).

These species are most commonly found in woodland habitats with well-drained soil and plenty of sunlight available. Typically, their nests are south-facing to maximise sun exposure and keep them warm. During winter, wood ants hibernate deep within their nests. They reemerge in spring and summer, often swarming on the nest in sunny weather to warm themselves.

How much space they need

Maintaining habitat connectivity is crucial for wood ants, enabling population dispersion across the landscape. This connectivity allows wood ants to move freely, find resources and establish new colonies, which is essential for their long-term survival and ecological role.

Forest fragmentation and human disturbances pose significant threats to these insects. Wood ants require forest patches to be within 200 metres of each other to facilitate their ability to form new nests through a process known as ​‘budding’, where a portion of the colony splits off to establish a nearby nest [1].

Background story

Wood ants are not legally protected in Britain. While they’re found across Britain, their range appears to be shrinking. For example, the red wood ant has disappeared from some parts of northern England, north Wales and the Midlands, while the European red wood ant (F. pratensis) has become extinct on mainland Britain and is now only found in the Channel Islands [2]. These declines are probably a result of habitat loss caused by changes in woodland management, deforestation and other human-induced disturbances.

In 2019 and 2021, red wood ant nests were relocated to Bishop’s Wood Country Park near Rickmansworth in Hertfordshire, England. Reintroduction projects like these play a vital role in rewilding woods and restoring essential ecological processes across Britain.