Although many people overlook them, moths are numerous and widespread, with over 2,500 species in Britain living in a wide range of habitats. They are a major part of our biodiversity and play vital roles in the ecosystem, affecting many other types of wildlife.
Both adult moths and their caterpillars are food for a wide variety of wildlife, including other insects, spiders, frogs, toads, lizards, shrews, hedgehogs, bats and birds. Night-flying adult moths form a major part of the diet of bats. Many birds eat both adult moths and their caterpillars, but the caterpillars are especially important for feeding the young. Some of Britain's favourite garden birds rely on caterpillars to rear their nestlings, with our blue tit chicks alone needing an estimated 35 billion a year!
Moth caterpillars have a great impact on plants by eating their leaves. This had led to many types of plant evolving special chemicals to make them less appealing to caterpillars and limit the damage. But moths also benefit plants by pollinating flowers while feeding on their nectar, and so help in seed production. This not only benefits wild plants but also many of our food crops, which depend on moths as well as other insects to ensure a good harvest.
Moths also play a vital role in telling us about the health of our environment, like the canary in the coalmine. Since they are so widespread and found in so many different habitats, and are so sensitive to changes, moths are particularly useful as indicator species. Monitoring their numbers and ranges can give us vital clues to changes in our own environment, such as the effects of new farming practices, pesticides, air pollution and climate change. To find out about moths and climate change, use the link on the left.