222 DISEASES OF DOMESTICATED BIRDS 
produces intense irritation. This occurs when fowls are placed 
in coops which have not been occupied for months and which harbor 
hungry ticks. The infested birds appear paralyzed, the wings droop, 
the feathers are ruffled and appetite is lost. Death may occur within 
a few days after such heavy infestation, but if removed from the 
ticks, the birds will recover. 
The discussion of the subject of harm induced by tick infestation 
alone, is complicated by the fact that in most countries ticks are 
the carriers of spirochetosis, which is described on p. 135. In the 
absence of positive information as to whether or not the fowl 
ticks of this country carry spirochetosis, it is not possible to state 
just how much injury is done by ticks alone and how much by a 
disease transmitted by them. 
Distribution. The tick occurs in the western half of Texas and 
in a zone extending westward along the southern part of New Mex- 
ico, Arizona and California. In the latter state the area extends 
northward along the western half of the state to a point slightly 
north of San Francisco. The area involved is indicated in Fig. 53. 
The distribution of the tick is thus seen to be confined to the warm 
portions of the arid and semi arid regions. In Texas it does not 
extend into areas where the annual rainfall exceeds 30 inches, which 
apparently prevents its extension into the eastern part of the state 
or eastward on the Gulf coast. Ticks may occasionally be shipped 
to northern states and find favorable conditions for a limited period. 
Elsewhere it occurs in Persia, Australia, Africa, South America, the 
West Indies, Mexico, Panama, India, Southern Russia and Rouw- 
mania. 
Life history of the tick. The habits of the fowl ticks resemble 
those of bed bugs in that they are night feeders and spend the day in 
cracks and other protected places. Thus considerable injury may be 
inflicted to poultry without the knowledge of the owner. 
Eggs are deposited in secluded places and in the summer, hatch 
in from 10 to 15 days. In the winter the hatching period may ex- 
tend over three months. The young seed ticks soon make their way 
to a fowl and attach themselves to the skin of the breast, thighs, or 
elsewhere and engorge with blood. This period of feeding, during 
which the ticks are constantly attached to the fowl occupies from 
3% to 10 days. When it is completed the ticks drop from the host. 
Before feeding they are light gray in color but after feeding they 
become dark blue, and are about one-tenth of an inch in length. 
After 4 to 9 days the seed ticks undergo a molt and develop into 
