You Lousy Stinking Louses...Er, Lice Quiz

Answer: True

This might seem like a trick question since there are many animals that can be found on all of the continents but Antarctica. However, there are 15 species of lice that infect penguins such as the Emperor penguin, which can be found in Antarctica. Most species of birds and mammals have an associated species or species of lice.

The many types of mammals that generally do not have lice are monotremes, pangolins, and bats.

Answer: False

On the contrary, lice are considered disease vectors and transmit diseases to their hosts. The human louse, for instance, is a carrier of typhus. In pre-modern times, sites of natural and man-made disasters would often see outbreaks of lice-carried diseases.

Other species of lice are often carriers of disease to their host species. Dog lice, for instance, can transmit the dog tapeworm.

Answer: False

Like other insects, the louse has six legs, found attached to the thorax section of the body. Sucking lice (surviving on blood or other bodily fluids) usually have a single claw on the end of each leg. Chewing lice (eating skin, hair or feather fragments, etc.) have one claw or two claws, depending on the species. Like other insects, lice also have three body parts--head, thorax, and abdomen.

Answer: False

A louse's lifespan is more accurately measured in weeks rather than years. For instance, a human louse may spend one to two weeks as an egg before being hatched and another one or two weeks as a nymph, growing towards adult size. The adult louse spends about an additional four weeks at that stage. If a louse could imagine another louse living for a whole year it would seem an impossibly long lifespan.

Answer: False

In fact, it is far more common for a louse to spend its entire lifetime on a single animal host. Most lice are obligate parasites and have evolved to require an animal host to survive. If the host animal dies, the louse has only a few days to find a new host. Since lice are usually wingless, a louse is most usually able to move from one host to another by "hitching a ride" on a flying creature, such as a flying insect.

Answer: True

An average sized louse (2.5 to 3.5 mm) is much smaller than an average cherry (about 20 mm). The louse is typically close in size to a sesame seed. On average a chewing louse is a little bit larger than a sucking louse. However, only a rare and extremely large louse would have a body length greater than 10 mm.

A louse is similarly light in weight at under one milligram, though the average female is usually heavier than the average male.

Answer: False

There are close to 5,000 species of lice. Of these, only about 800 predominantly infect mammals. Many species of lice have evolved to feed from specific bird or mammal species. The typical bird species hosts three to six species of lice as opposed to the typical mammal species which only hosts one to three species of lice. Human beings, for instance, host two species: Pediculus humanus (which includes the subspecies of head lice and body lice) and Pthirus pubis (pubic lice).

Answer: True

The head of a chewing louse is usually wider than its thorax as compared to the head of a sucking louse which is usually narrower. Another difference between the two types of lice are specific mouth parts that have evolved for different types of feeding.

In addition, some types of sucking lice lack eyes. One similarity is that both type of lice tend to have oval-shaped flattened bodies.

Answer: True

In addition to liking the darkness, the typical louse responds positively to the warmth of the host body. The louse also seems affected by the smell of the host body. It is thought that the peculiarities of the host body's fur or feathers may help to guide the louse in some way.

A particularly heavy infestation of lice may make it more difficult for the host animal to regulate its own body heat.

Answer: True

Nits, or lice eggs, are cemented by the mother to the hair or feathers of the host animal with a special type of saliva. The nit will hatch about 9-12 days after being laid, producing a nymph which will later grow into an adult louse. In some species, the male fertilizes the female's nit.

In other species, parthenogenetic reproduction occurs (that is, from unfertilized eggs). In most lice species, females are more common than males.