Stonefly larvae live in benthic zones (substrate level) of well-oxygenated streams and lakes. They have flattened bodies and segmented abdomens with 6 legs and 2 long cerci at the end of their abdomen, like tails. They have tuft-like gills, usually on the underside of their body. Stonefly larvae usually have chewing mouthparts as the different species will eat plant material and/or other aquatic invertebrates. Stonefly larvae typically inhabit clean, flowing streams and rivers, with some species preferring lakes and ponds. They sit under submerged objects such as rocks. Stonefly larvae are common and widespread across the UK.