Louse

Louse is the common name for 3000 different species of parasitic insects in the order Phthiraptera. It is parasitic to both humans and other mammals, and is extremely infectious.

Body Design
There are many different types of lice but they all have common body design. Usually it's the size of a pinhead and it's oval shaped with 3 legs and claws each side of it's body. All the adult lice have a head, thorax, and abdomen. It's head has anterior piercing mouth part that can pierce through the scalp or skin of it's prey. Lice has a flat body which can help lice to stick to it's prey's feather or hair. The color of lice is depends on it's prey's body color. which means that all animals with white hair has white lice, and those with black hair almost always has black lice. The blood sucking lice has three stylets within it's head. It has small proboscis with the tooth-like processes which is for holding the prey when it's sucking the blood out of it's prey but the other lice has little different mouthpart, for example, the elephant lice has different mandibles at the end of a long proboscis than the other lice. Lice uses antennae as clasping organ to hold female when they are mating. Since the female lice does not have a defined ovipositor it has lobes at the end of it's abdomen with can be used when they are laying eggs in the specific area.

Life Cycle
Head louse has three stages egg,nymph, and adult. Head Louse's eggs are called Nits, they are often confused as a dandruff. you cannot wash the nits off of your hair. Female louse lay nits on the base of the hair, closest to the scalp. Nits are less than 1cm long and they take about a week to hatch. when the nits are hatched you can see nymph of a louse. In order to become adult they have to molt about three times, but it only take 7 days for them to molt three times and become an adult. The adult louse has six legs and the color of the louse depends on the color of the head that nits were hatched. Female louse is usually bigger than the male louse and female louse can lay 8 nits per day. Nits have protective shells that can not be ruined by lice products. Adults can live up to 30 days on it's prey but without blood it will die in i or 2 days. In order to survive it has to suck on blood several times a day.

Ecology
Head lice spread through direct contact, head to head. Head lice can stick on to hats, coats, and brushes. Lice can reduce it's host's life expectancy also it can transfer microbial diseases lice sticking it's teeth in to it's prey. Scientists are using lice for study of contagious pathogens. Lice's mouthpart is well adapted just for sucking blood off of it's prey. When it bite the prey it injects salivary secretion to prevent blood from become dense while it's feeding. The stylets goes back into it's head when it's done with eating food. The feather-eating mallophaga can digest protein on it's feather(keratin).

Treatment
When you are infected by a lice all household members avoid contact with the infected. Apply the every treatment you can get from the pharmacy, doctors are recommending infected to use more than 2 different types of treatment. there are many pesticide treatments that you can get from anywhere but it may not harm nits. other than using treatment you can use wet comb to comb your hair once a week or often and use hair dryer to dehydrate the lice and the nits.

Video
This is a common head louse. The video was taken with a USB microscope with the louse stuck to piece of clear tape to keep it from moving. tWFBLo-ySpw