Lice are obligate ectoparasites of every avian and most mammalian species. They are only a few millimeters long and like [[Fleas|fleas]], are wingless but unlike [[Fleas|fleas]] are dorsoventrally flattened. | Lice are obligate ectoparasites of every avian and most mammalian species. They are only a few millimeters long and like [[Fleas|fleas]], are wingless but unlike [[Fleas|fleas]] are dorsoventrally flattened. |