Arizona \ 
Exp. Sta./ 
LIFE HISTORY OF THE KANGAROO HAT. 
15 
Occasionally a bold individual is found, as in the case of one which 
came out repeatedly, even after being flashed twice in the same night. 
Certain peculiar physical characteristics suggest a relationship to 
sense reactions. On these, however, the authors are not prepared to do 
more than offer suggestions for future work. The extremely large 
mastoids found in kangaroo rats suggest a connection in sonic way 
with special developments of the sense of hearing or of balance. It 
may be noted that an intermediate condition between the kangaroo 
rats and the majority of rodents in respect to this character is to 
be found in the pocket mice (Perognathus) , which belong to the 
same family. Herein lies a field for some interesting experimental ion 
and discovery. 
The small, pointed nose might suggest a not overkeen sense of 
smell, and there appears no reason to believe that this sense is par- 
ticularly well developed. However, the turbinate are very complex. 
The vibrissa? are long and sensitive, and may indicate a special devel- 
opment of the sense of touch as an adaptation to nocturnal habits 
and to life in an underground labyrinth. The long, well-haired tail 
doubtless serves as an important tactile organ as well as a balance. 
MOVEMENTS AND ATTITUDES. 
Movements and attitudes are characteristic. As a kangaroo rat 
emerges from the burrow a reason for the relatively large size of the 
opening is seen in the fact that, kangaroolike, the animal maintains 
a partially upright position. Its ordinary mode of progression is 
hopping along on the large hind legs, or, when in the open and going 
at speed, leaping. When moving slowly about over the mound, as 
if searching for food, it uses the fore legs in a kind of creeping move- 
ment. It appears to be creeping when pocketing grain strewn about, 
but close observation shows that the fore feet are then used for sweep- 
ing material into the pockets, reminding one somewhat of a vacuum 
cleaner. When it assumes a partially upright position the fore limbs 
are usually drawn up so closely that they can be seen only by look- 
ing upward from a somewhat lower level than that occupied by the 
animal. The slower movements of searching or playing about the 
mound are occasionally interrupted by a sudden leap directly upward 
to a height of H to 2 feet, often with no apparent reason other than 
play. This is. however, a fighting or guarding movement;, though 
indulged in for play. The play instinct seems to be well developed, 
and in evidence on any moonlight night when actual harvesting oper- 
ations are not going on. 
STORING HABITS. 
Probably no instinct is of greater importance to the kangaroo rat 
than that of storing food supplies. When a crop of desirable seeds 
