Re: where lices come from? why people get lice in their hair?

    Lice are  wingless insects that  occur in all areas of the world and 
in all socio-economic classes. People of all ages and from all walks of 
life can be infested, however children and their family members are the 
ones usually affected.Lice spread from human to human most often by direct 
contact with an already infested person. Anyone can catch head lice. Head 
lice happen where people live, learn, work or play together. Head lice 
cannot fly, hop or jump; they spread from person to person by head to head 
contact. Contact is common during play at school and at home (slumber 
parties, sports activities, at camp, on a playground).  Alternately, 
transmission can occur by wearing infested clothing, such as hats, 
scarves, coats, sports uniforms, or hair ribbons; by using infested combs, 
brushes, or towels; and by lying on a bed, couch, pillow etc. where an  
infested  person has lain. 
    Body lice (_Pediculus humanus_) are restricted most often to the human 
body and head (some authorities believe the head louse is a separate 
species). Crab (pubic) lice (_Phthirus pubis_)  are most often restricted 
to the pubic region, but may spread to the armpits, facial hair (beard, 
etc.), eyebrows, and eyelashes. Infestations with lice are not a serious 
problem (as long as the lice are not infected with a disease), but they 
can cause a number of uncomfortable symptoms, including skin irritations 
and intense itching. The body louse will serve as the vector for typhus 
(caused by _Rickettsia prowazekii_), trench fever (caused by _Rochalimaea 
quintana_, a rickettsia), and relapsing fever (caused by a spirochete, 
_Borrelia recurrentis_). Severe epidemics of these diseases have occurred 
throughout history, particularly during wars, so lice and the diseases 
they spread have played an important role in human history.
     Incidently: “lice” is the plural of “louse”,  so   “lices” is 
incorrect!


 http://www.hsph.harvard.edu/headlice.html http://hna.ffh.vic.gov.au/phb/9908014/ http://onhealth.webmd.com/conditions/resource/conditions/fulltext/item%
2C395.asp http://www.microscopy-uk.org.uk/mag/articles/louse.html http://www.msue.msu.edu/msue/imp/mod02/01500559.html