Where do insects live besides land habitats?

Insects are highly adaptable and have successfully colonized a wide variety of non-terrestrial habitats, primarily within freshwater environments. While they are fundamentally terrestrial in origin, they have evolved numerous physiological and structural modifications to thrive in water.123

Aquatic and Semiaquatic Habitats

Insects occupy diverse freshwater settings, ranging from cold mountain streams and stagnant lowland ponds to hot springs. Their presence in these environments is supported by several specialized adaptations:1

• Respiration: Many aquatic insects, such as water beetles, carry air supplies in chambers under their wings or trap air against their bodies using dense hairs, which can function like a physical gill. Others, like caddisfly and mayfly larvae, possess external tracheal gills, while dragonfly larvae utilize internal rectal gills.34
• Locomotion: Aquatic species often feature modified legs that serve as oars for swimming, or specialized structures that allow them to "walk" on the surface film of water, such as water striders.35
• Extreme Environments: Some insects are found in brackish water, and certain fly larvae can even survive in pools of crude petroleum.1

While most insects avoid saltwater, they are the primary land animals found in salt marshes, where they often move to higher ground or fly away to escape tidal immersion.6