190 THE ANIMALS AND MAN 



that normally float on the surface and to the adults trying 

 to issue from the pupal shells. About one pint of kerosene 

 will effectively cover fifteen square feet of water. Old cans 

 or pails or casks in which rainwater collects should be re- 

 moved; garden water taps should not be allowed to leak; 

 water troughs should be kept running or be emptied every 

 few days. 



If the mosquitoes come from a marsh or large pond com- 

 munity efforts at drainage are in order. Certain little fishes 

 called "millions" or "top minnows" (Fundulus species) are 

 great mosquito-wriggler eaters, and a pond well stocked 

 with these, or indeed almost any kind of top feeding fishes, 

 will not produce many mosquitoes. 



There are no very satisfactory ways of killing or driving 

 away the winged flies. Smudges and pyrethrum powder do 

 some good. Ill-smelling oils like pennyroyal smeared on 

 hands and face may be helpful, but they are very disagree- 

 able to most persons. The real way in which to rid a region 

 or community of mosquitoes — which is equivalent to rid- 

 ding it of all danger from malarial fevers — 'is to abolish the 

 breeding places or keep them covered with oil through the 

 mosquito breeding season. 



An excellent recent book about injurious insects and the ways to 

 fight them is "Our Insect Friends and Foes," by J. B. Smith. 



