All amphipod species prefer humid habitats. In general, the different kinds of amphipods have flat bodies and large compound eyes on the sides of their heads. Most amphipods use a defense mechanism known as impulse tail, through which and using their abdomen, they propel themselves to get away from a predator. However, since the amphipods belong to an order composed of more than 8,000 species, their habitats, characteristics and eating habits vary. Although the word amphipod translates “two kinds of legs”, the different species of amphipods have different amounts of them. . Each species also walks differently, since its movements are in direct relation with its extremities. Some amphipods walk upright and very slowly, while others swim and move quickly by using three of their pleopods, or legs. The adult amphipods can reach 20 millimeters in length. Those who live in the water are usually white, although some may also exhibit light brown, green, dark brown or black. Most amphipods turn red when they die.
The amphipods can thrive in marine environments and in humid earth. Other species can be found in house gardens and under pots. Some amphipods, such as whale lice, establish their homes on the skin of marine mammals.
Some amphipods are herbivores while others are carnivores. The amphipods that live in the sand, the mud and the humidity of the ground, feed on bacteria. Other species are scavengers and feed on dead plants and animals.
For breeding purposes, male amphipods usually have large bulging eyes, or chemical receptors on their antennae. The males look for the females and grasp them using their limbs. Males and females remain tied during their consummation ritual. Although most female amphipods produce a single generation of offspring, there are species that can produce several generations in a period of five months.