12 BULLETIN 553, U. S. DEPARTMENT OF AGRICULTURE. 



(3) Through the carrying by man of mites on his clothing, thereby 

 starting an infestation. 



(4) Through the carrying of mites by sparrows, and probably by 

 pigeons, from one place to another in their feathers. 



(5) By horses, cattle, dogs and cats, and certain wild animals, such 

 as foxes, skunks, and weasels, which possibly act as mechanical car- 

 riers. 



(6) By migration of the mites to buildings in contact or close 

 proximity to infested premises. 



The most important method of spread, without doubt, is by in- 

 fested fowls. In general, it may be said that any carrier may be- 

 come of greater or less importance, depending upon its closeness of 

 association with an infestation and the degree of the infestation. 

 Also, the danger of infestation increases the nearer clean fowls are 

 located to infested ones. 



OTHER HOSTS. 



The writer has had thousands of mites crawling on his skin but has 

 no knowledge of having been bitten by any of them ; the feeling pro- 

 duced by the crawling mites, however, is very disagreeable. Other 

 people testify that the mite bites them. While turkeys are attacked 

 freely, chickens are favored, and other poultry (pigeons) are fed 

 upon. Stock in barns abutting on chicken houses are at least irri- 

 tated by mites. 



FOOD OTHER THAN BLOOD. 



Does the mite feed on anything besides blood? Inasmuch as a 

 number of writers have said that the mite feeds on filth of different 

 sorts, a few experiments were undertaken to get some evidence on the 

 question. 



Mites in different stages were put with moist and dry hen drop- 

 pings, and with feed such as cornmeal and bran, and were watched 

 closely for several days. Mites were then tried with white of egg 

 and yolk of egg; a small quantity being put in a tube with about 50 

 mites. The mites did not appear to feed,-nor, after several days, did 

 they look as if they had fed on any of these substances. Mites were 

 put in a vessel with a partially dried egg but did not appear to feed 

 on it. Mites with access to filth, dirt, etc., lived no longer than mites 

 without access to these substances, and the} 7 did not breed in this 

 material. 



Inasmuch as the mouth parts of the mite are fitted for piercing 

 and sucking, a fresh egg was cracked so as to expose the amnion, to 

 see if the mite would be able to draw nourishment from it. Careful 



