Common Insect Enemies 125 



and gets started in man by the bite of a flea. How many 

 other diseases we acquire in a similar manner we don't know, 

 but a mass of evidence is accumulating to show that many 

 animals and birds, both wild and domesticated, can act as 

 carriers of human diseases, and that these diseases are trans- 

 ferred to our bodies by the bites of fleas, ticks, and mites. 



There are several hundred species of fleas, but they are 

 all similar in habits and resemble each other in appearance. 

 If all species would remain exclusively with their preferred 

 hosts it would not be so bad. But they don't. A rat flea 

 may prefer a rat to a man, but when a rat dies and the fleas 

 leave him, they'll become companions of men if no rats are 

 readily available. And as for cat and dog fleas, they make 

 themselves right at home in our houses. 



The eggs of fleas are laid on the body of the host ani- 

 mal, but they either fall off or get shaken off to the ground or 

 floor. Thus, they become scattered about the floors of dwell- 

 ings and the sleeping places of infested animals. Carpets, 

 rugs, upholstered furniture, and even your bed may become 

 depositories of flea eggs. And here the eggs hatch to larvae. 

 The larvae are not parasites: they find enough food in the 

 decaying animal and vegetable matter in the dirt in which 

 they live. But when they become adults, they change their 

 habits. Now they live on animals. 



Since dogs and cats are about the only animals that 

 people ordinarily permit to share their homes, the common 

 fleas that you are likely to encounter are dog or cat fleas. Of 

 course, if rats inhabit your premises there will probably be 

 some rat fleas around, too. 



To get rid of fleas on dogs, dust the animals thoroughly 

 with 10% DDT powder — about 1 tablespoonful is sufficient 

 for an average-size dog. The fleas will start to die in about 



