ANIMAL BEHAVIOR—ERNEST P. WALKER 291 
bats are in a good position to take off for flight, for they are generally 
at an elevated location and have merely to let go with their toes and 
spread their wings to be in full flight. 
I have noticed that the nine-banded, the six-banded, and the hairy 
armadillos (Dasypus and Huphractus) all tremble almost continuously 
in their sleep, particularly when lying on their backs or sides, as they 
often do. This is unique among mammals with which I am ac- 
quainted, but I have no theory to explain it. 
Malayan porcupines (Acanthion brachyurum) like to sleep side by 
side and have an interesting method of avoiding the spines of another 
that has already lain down. Each succeeding one merely faces in 
the opposite direction from the last one in the row. I have seen as 
many as five lying asleep in such alternating head and tail positions, 
but when I tried to take their pictures in this arrangement I usually 
disturbed some of them, so that I have never been able to photograph 
more than two together (pl. 15, fig. 2). 
The tiny bat parakeets (Loriculus) sleep hanging head downward, 
clinging to the perch by their feet. 
Of all the small mammals I have observed the females are much 
more particular regarding the nest than the males. The females will 
move it about, cut on the nest box, assemble nest material and keep 
it well shaped into a snug nest, whereas most of the males are far less 
particular, usually working on the nest only enough for it to be 
passably comfortable. Of course, my wife noticed this before I did 
and pointed out that females have stronger instincts for home main- 
tenance than males. 
Most mammals, when they have the opportunity to awaken natur- 
ally, like to sit and “think,” or perhaps just sit, like many people 
who cannot start off ‘in high gear.’”’ Those that I have observed, 
after about half an hour start normal activity. 
Hibernation was discussed briefly in my previous paper on Animal 
Behavior and has been extensively treated in other literature so will 
not be further mentioned herein. 
CONCLUSION 
The better our knowledge of animal habits and behavior, the better 
we are prepared to cope with the problems in connection with animal 
life and the administration of resources in which animals play a part 
of greater or less importance. Biologists are constantly being con- 
fronted with problems of how to control, circumvent, keep away, or 
increase wild life. The problems may be simple or very complex, 
but are always interesting. 
Wildlife administration has become an important branch of national, 
State, and local government work for we have come to realize that 
many of the forms are highly beneficial and should be protected and 
