SEASONAL HISTORY AND HABITS. 21 
SEASONAL HISTORY AND HABITS. 
For convenience in tracing the life cycle of the Rocky Mountain 
spotted-fever tick we will begin with the appearance of the flat or 
unengorged females and males which appear with the first warm 
days of spring. It should be remembered that these ticks have 
remained dormant throughout the winter months. When they are 
rendered active during the warm spring days they are immediately 
ready to attach to an animal and engorge. Some of these ticks 
pass the winter in places where they are not readily reached by the 
warmth of the sun. Such specimens become active later than others. 
Emergence from winter quarters is therefore gradual, usually 
extending over a period of a few months, beginning about the 1st 
of March. 
The time of the beginning of activity in the spring is also depend- 
ent to a considerable extent upon the relative earliness of the season 
and upon the locality. In lesser altitudes, and at the southern limit 
of the range of the species, activity may begin as early as the middle 
of February, while in the Bitter Root Valley it is probable that the 
ticks seldom become active in numbers before nearly the middle of 
March. 
After leaving their winter quarters the adult ticks begin crawling 
about and usually ascend brush to await a host. They may crawl 
upon trees or other objects so as to get several feet above the ground. 
In all ticks the anterior legs have well-developed sense organs 
located near their tips. These front legs are used as feelers. When 
the tick is disturbed it immediately begins to wave them in an 
endeavor to catch any passing object. 
Having found a host, the ticks crawl about upon it until a suitable 
place for attachment is found. On cattle they are usually found in 
numbers on the dewlap, between the fore and hind legs, and along 
the belly. On horses they are commonly found between the legs 
and sometimes in the mane. They may, however, attach to any part 
of the host.* 
Attachment to the host is accomplished by means of a spiny 
beak, which lias an opening in the end through which the blood 
of the animal is drawn. In from 4 to 8 days after attaching the 
males begin searching for mates. In order to fertilize the females 
they crawl beneath them, and after mating usually attach to the 
animal immediately under their mates. When the females have 
become one-half engorged the blood is rapidly imbibed, and com- 
plete engorgement is reached in a very short time, after which they 
loosen their hold and drop to the ground. 'Fable I shows the time 
required for the engorgement of females on different hosts and 
during different times of the year. 
