WOOD-RATS, PACK-RATS, ETC. 99 
of their habitations, which are conical pyramids 
about three feet high, constructed with dry branches, 
which they collect with great labor and perseverance, 
and pile up without any apparent order; yet they 
are so interwoven with one another, that it would 
take a bear or wildcat some time to pull one of these 
castles to pieces.’’ 
‘‘The very playful character of this species,’’ re- 
marked Audubon, ‘‘its cleanly habits, its mild, promi- 
nent and bright eyes; together with its fine form and 
easy susceptibility of domestication, would render it 
a far more interesting pet than many others.’’ 
West and southwest of the Plains live many 
closely related species, some of which inhabit 
‘the mountains, others only timbered valleys, 
while still others are restricted to desert val- 
leys. All erect more or less elaborate and 
often conspicuous houses, sometimes in the 
branches of trees—a safer place than on the 
ground. oe 
Vernon Bailey discusses upon them thus: 
‘For houses they heap up a bushel or more of sticks, 
stones, cow-chips, cactus, bones, or other materials 
which the animals can carry and pile up as a protect- 
ing cover for their nests and burrows in the ground be- 
neath. Cactus and thorny branches, if available, are 
always a conspicuous part of the building material. 
The house is usually occupied by one old rat, a pair, or 
