One group of families lives in tubes spun from silk glands in their legs. Sometimes forming colonies, these amphipods when alarmed can completely conceal themselves inside the tubes that may be 2-3 times their body length. The only part of the body that protudes from the tubes is the antennae that have long hairs which are thought to capture food particles. Other amphipods, less commonly seen than the caprellideans and gammarideans of shallow marine environments are, the Hyperidea. These are planktonic and translucent, often with enormous eyes as big as the rest of the body.
Some groups live their lives attached to marine mammals.
These whale-lice are ectoparasites which cling firmly to, and feed on, the skin of whales. Unlike other amphipods, whale-lice cannot swim so once the juveniles leave the brood chamber of the female they attach themselves close by. The ways in which amphipods move depends on the arrangement of their legs. Most walk upright using most of the thoracic legs but this is very slow. Swimming using the three pairs of pleopods is much faster.