Insects play vital roles beyond being food for animals

A new review highlights the diverse and often overlooked ways insects support animal life, far beyond their role as a food source. Researchers from an international working group examined how declines in insect populations could affect vertebrates, from birds to mammals.

Insects act as ecosystem engineers, creating and maintaining habitats for other species. Termites and ants build complex structures that shelter reptiles, birds and amphibians. Termite mounds, for example, offer climate-controlled nesting sites for parrots and egg-laying spots for reptiles, while their nutrient-rich soil benefits burrowing animals like aardvarks.

Defense and health

Some vertebrates rely on insects for protection. Horned lizards use chemicals from ants to develop a toxic defense against predators, while certain birds nest near wasp colonies to deter threats. Insects also contribute to health—chimpanzees have been observed using them to treat wounds, suggesting undiscovered medicinal properties.

Insects also play a key role in waste removal and disease control. Dung beetles and other species decompose carcasses and waste, reducing parasite spread. Dragonfly larvae help control mosquito populations by preying on their young, while in Australia, mosquitoes were used to spread a virus that curbed invasive rabbit numbers, aiding native marsupials.

Food and ecosystem balance

As a food source, insects are vital, forming the bulk of diets for many species, from songbirds to grizzly bears. Indirectly, they support food chains by pollinating plants like fig trees, which feed over 1,200 vertebrate species. Disruptions in insect populations can even alter predator-prey dynamics, as seen when invasive ants disrupted plant relationships, changing elephant and lion behavior.

The review, published in Nature Reviews Biodiversity, underscores that conserving insects is crucial for maintaining biodiversity and ecosystem stability, benefiting both wildlife and humans.