LICE 137 



your own house and grounds and make sure that no stand- 

 ing water is near, for mosquitoes rarely fly more than a 

 few hundred yards from where they hatch. The introduc- 

 tion of goldfish, sticklebacks, or other small fish will soon 

 rid ponds of mosquitoes. 



Yellow fever, which at one time was a terrible menace in 

 this country, is carried by another kind of mosquito. We 

 will discuss this more fully in " Civic Science in the Com- 

 munity." 



Fleas. The ordinary dog and cat flea should always be 

 considered a menace to health, for it may carry bubonic 

 plague and infect people with it. 

 Plague is a disease of rats, but is 

 spread by fleas which live upon them. 

 Fortunately this disease is not prev- 

 alent in this country, although in Flea which trai T smits bubonic 

 some parts of the world, particularly plague from rat to man. 

 in China, it is killing many thousands of people yearly. 

 Fleas flourish in dust, under carpets, in cracks, and par- 

 ticularly where dogs and cats sleep. Mats on which these 

 animals sleep should be constantly dusted and cleaned, 



and benzene or pyrethrum powder may be used 



to fight the pests. 

 Lice. Lice are wingless insects which have 



come into prominence during the World War. 



The body louse is the " cootie " of the soldier. 



It becomes a very serious pest to those obliged 



to live in dirty surroundings, and can be 

 The "cootie." era di ca t e d only by having the clothes sterilized 

 and by treatment of the body with ointments. The head 

 louse sometimes found in the heads of school children is very 

 annoying and hard to get rid of. The " nits " or eggs are 



