244 
JOURNAL OF MAMMALOGY 
in a circle that kept it in close touch with the nest. If the nest was 
destroyed the rat could then be driven away immediately, usually to 
a small refuge nest high up in the trees. 
NESTS 
The dwelling of this woodrat and the methods used in its build- 
ing are of much interest, even though these nests appear to the casual 
observer to be nothing more than piles of dry sticks and trash. The 
animals are versatile in their adaptability to their surroundings, in 
the methods of construction, and in the utilization of materials; and 
are exceedingly dextrous in the handling of large and unweildy objects. 
Before going into details of the structure it is necessary to know some- 
thing of the requirements of the animals. They appear to be sociable 
by nature. In one case I found evidence of two families occupying 
one large nest. Frequently hard and well worn paths will be found 
leading from one nest to another, indicating intercourse between 
them. Usually the nests are to be found in colonies, isolated nests 
being exceptions. 
In certain localities where I have collected botanical spec'mens the 
nests are bu lt in every thicket, against trees and around stumps, and 
in the branches of the trees, in fact in every conceivable place that 
affords the needed support and protection. The methods of utilizing 
these facilities are often unique and ingenious. The preferred places 
are in the dense forest but sometimes the nests are built on open rocky 
ledges. In the latter case they are solitary and small. 
Conditions to be met in the selection of sites for individual nests 
and for colonies are the sources and abundance of food supply, the 
general safety and security of the nests, and the ease in securing the 
needed building materials. Proximity to water is not essential and 
the animals often travel considerable distances to it. The presence 
of humans is not taken into consideration, although they delight in 
raiding habitations and belongings. 
I have on occasion come upon rats beginning the construction of a 
nest. One pair began at the base of an oak and made an excavation 
on the downhill side that ran back at an angle a foot in the hard, finely 
pulverized, rocky soil and was so placed as to receive the greatest 
amount of protection from the base of the tree. They next gathered a 
large number of small twigs, most of them freshly cut, which they piled 
in such a way around the opening as to form a cham^ber above it. 
This fine material they then covered with larger and coarser material 
