Leaflet No152 
U.S. DEPARTMENT 
OF AGRICULTURE 
By F. C. BisHopp, principal entomologist, in charge, Division of Insects Affecting 
Man and Animals, Bureau of Entomology and Plant Quarantine 
Fleas are troublesome pests of man and domestic animals, and 
certain species that infest rats and other animals carry a number of 
serious diseases of man, such as bubonic plague and endemic typhus, 
or act as hosts for internal parasites. 
Kinds and Habits of Fleas 
There are many different kinds of fleas, but most of them have 
somewhat similar habits. Some confine their attacks to certain kinds 
of birds or animals, while others will suck blood from almost any 
warm-blooded animal. There are 
three kinds of fleas that commonly 
become serious pests of man in this 
country. These are the dog flea 
(Ctenocephalides canis Curtis) (fig.1), 
the cat flea (C. felis Bouché), and 
the human flea (Pulex irritans L.) 
(fig. 2). In the South the stick- 
tight flea (Kchidnophaga gallinacea 
Westw.) (fig. 3) infests poultry 
and occasionally annoysman. The 
dog and cat fleas are very similar 
in appearance and they feed in- 
terchangeably on dogs and cats. 
These are the fleas that are responsible for house invasions in the 
Eastern States. The human flea may live on many different animals. 
Often it is associated with hogs and breeds in the litter in hog houses. 
It also lives on dogs and cats and on wild animals, such as coyotes, 
badgers, and skunks. This is the flea most frequently found annoy- 
ing man in the Mississippi Valley, in Texas, and westward to the 
Pacific coast. 
All fleas require the blood of birds or animals in order to reproduce. 
There is no true ‘‘sand flea’ breeding in the sand without animals 
upon which to feed. 
FIGURE 1.—Dog flea (male), greatly enlarged. 
Washington, D.C. Issued November 1937 
16474°— 37 
