1918] Camp: Burrows of the Rodent Aplodontia 529 
pulled just within the burrow entrances lead one to believe that the 
timid mountain beaver does much of its feeding in the comparative 
security of its burrow. 
A singular habit has been noticed in connection with the storage 
of food. In a burrow excavated at Point Reyes (see fig. 2) the 
entrances of two of the food storehouses were found plugged with 
large pellets of earth evidently manufactured by the animal for this 
especial purpose. These earthen balls were one to two inches in diam- 
eter and very hard and dry, evidently from having been handled a 
good deal. It is curious that the outer burrow entrances are not 
similarly plugged. 
Gibbs (in Suckley, 1860, p. 100) was the first to note a peculiar 
hay-making habit among the mountain beavers he found living at the 
top of Yakima Pass, Washington. ‘‘Near their abodes,’’ he says, 
“were small bundles of some herb or plant eut with nicety and laid 
out on logs to dry or wilt,’’ and Lyon (1907, p. 91) and Bretherton 
(1895, p. 124) confirm this. Townsend (1887, pp. 174-175) thought 
he recognized the hay-making instinet among the aplodontia he 
observed on the North Fork of the Feather River in California. 
Elliot (1899, p. 252) makes particular notice of the hay-making 
habit and adds that the cured stems of the lily, which he saw Aplo- 
dontia rufa olympica using, may be employed either for food or as 
bedding in the nests. Stephens (1906, p. 95) writes: ‘‘I saw bunches 
of plants laid up on low bushes to dry, commonly over entrances to 
burrows, most of these not being much dried, as if they had carried 
them in as soon as they were well wilted’’—this in regard to Aplo- 
dontia rufa californica, on the headwaters of the Carson River in 
Alpine County, California. Miss Kellogg (1916, p. 372) speaks of 
the habit in question as occurring among the colonies of Aplodontia 
rufa rufa discovered on the South Fork of the Salmon River in Siski- 
you County, California. She says: ‘‘We found the mountain beavers 
making what we called ‘hay’—large bunches of green plants of various 
kinds cut up and spread out as if to dry and to be used later.’’ 
From observations of the nests and of feeding habits my own con- 
clusion is that the animal does not eat dried food but uses its hay 
for nest-building material. 
The manner of feeding has been observed in the captive animal 
and partly determined from the evidence of cuttings. The rodent 
usually sits back upon its short tail, with the back curved, the hind 
feet extending out in front, soles forward, and the fore paws grasping 
