Louse, line drawing.
- Andrew Howells
- © Australian Museum
Lice belong to the Order Phthiraptera.
What do lice look like?
- 0.5 mm - 10 mm in length but most are shorter than 5 mm.
- Ovoid or the abdomen is swollen making it look like a lopsided dumb-bell.
- Flattened as if pressed from above.
- Body appears hard.
- Very short; sometimes held in a groove hence often difficult to see.
- Thread-like, or club-like; never longer than head.
- Very small or absent.
- For chewing or munching, or a pointed tube for piercing and sucking.
- Six legs.
- Have modified hook-like claws for clinging to feathers or fur.
- Cerci (tails) absent.
Where are lice found?
- On mammals and birds clinging to hairs or feathers.
- Often restricted to one host and usually favour one specific part of the host's body.
What do lice do?
- They are external parasites and are often found groups around food source.
- When disturbed they may run but generally they cling to hair or feathers.
- They feed on feathers, hairs, skin flakes and blood. Some will feed on eggs of other lice species.
- They are active day and night.
What looks similar?
- Psocids can be distinguished from lice by their long thread-like antennae, and ovoid body. They also do not occur as external parasites, but may accidentally crawl on birds or mammals.
- Fleas can be distinguished from lice as they are flattened from the sides and jump when disturbed