12 BULLETIN 1091, U. S. DEPARTMENT OF AGRICULTURE . 
rhythmically after a very short interval, suggesting the distant gal- 
loping of a horse. After continuing in this way for a short time, the 
animal turned quickly about, with its head in the opposite direction, 
and began tapping. It appeared to pay little attention to the light, 
but finally gave a sudden bound and entered one of its holes about 4 
feet from the one in front of which it had been standing. 
Vorhies has repeatedly noted when watching for the appearance 
of a kangaroo rat at night that this sound invariably precedes the 
rodent's first emergence into the open, and often its appearance after 
an alarm, though when the storage season has begun and the kangaroo 
rat is carrying loads of grass heads or other material into its den, 
it regularly comes out without preliminary signaling. Vorhies has 
also observed it making the sound while on top of the mound, and 
certainly not digging, but was unable to see how it was made. 
Voice. 
No data concerning any call notes or sounds other than those de- 
scribed above are at hand, with the following exception: Price (in 
Allen, 1895, 213), who studied the habits of the animal in the moon- 
light, at Willcox, Ariz., says that a low chuckle was uttered at inter- 
vals ; and Vorhies has had one captive female that would repeatedly 
utter a similar chuckle in a peevish manner when disturbed by da} , 
and one captive male which, when teased into a state of anger and 
excitement, would squeal much like a cornered house rat. Vorhies 
has spent many moonlight hours observing kangaroo rats, but with- 
out ever hearing a vocal sound uttered by free individuals. 
DAILY AND SEASONAL ACTIVITY. 
The kangaroo rat is strictly nocturnal. An observer watching 
patiently by a den in the evening for the animal's first appearance 
is not rewarded until darkness has fallen completely, and unless the 
moon is shining the animal can hardly be seen. Were it not for the 
white tail-brush of spectabilis and its white belly when upright on 
the hind legs and tail, one could not as a rule see the animal at all 
when it makes its first evening appearance. With the first streak of 
dawn activity usually ceases completely and much more abruptly 
than it began with the coming of darkness, but on a recent occasion 
Vorhies observed that a kangaroo rat which did not appear until 
near morning remained above ground until quite light, but not fully 
daylight. On removal of the plug from the mouth of a kangaroo rat 
burrow, one may sometimes see a fresh mass of earth and refuse shoved 
into the opening from within. As often as not, however, even this 
unwelcome attention does not elicit any response by day, the great 
majority of the burrow openings of this species, as observed by the 
authors, remaining permanently open. 
