Muskrat 
midway even in the coldest weather, when everywhere except 
in midchannel the water is hard frozen to the bottom. 
The upper chamber in the cabin is lined with soft grass and 
moss and here the owners spend much of their time in winter 
curled up asleep, often three or four together. Some of the 
smaller cabins have only the upper chamber without any down- 
ward passage whatever; others are large enough to contain four 
or five apartments at least. Many of them are built in low 
willow trees or on rough frameworks of sticks which the musk- 
rats arrange among the alders; and here they exhibit much of 
the constructive ability of the beavers, cutting their wood on 
shore in a similar manner and often towing it long distances to 
their building sites where they wattle it firmly between the alder 
stems for a foundation. 
Cabins so placed are generally composed largely of cattail 
stalks and green twigs, while those on the ground are more 
often built of mud and pieces of sod. The cabins are not much 
used except at times of high water and in winter, though I doubt 
if they are ever wholly abandoned at any season. So long as 
the streams remain frozen, the muskrat is practically free from 
care and danger. The temperature about him hardly varies a 
degree whatever the weather may be above the ice. He knows 
nothing of snowstorms or sleet or high winds while the ice 
holds firm, though the rushing wind-driven water may be deep 
over the ice in times of freshet. Down where he is at work 
it flows with the same gentle motions as in summer, barely 
swinging the water weed and cresses as it slips between them. 
There is generally plenty of air to be had close up under the 
edge of the bank beneath the ice, and when this is not within 
reach, he has only to expel the air from his lungs against the 
undersurface of the ice when it is quickly purified by contact 
with the freezing water. 
It frequently happens that the water, falling away from the 
ice, leaves extended caverns the width of the stream at high water 
and roofed over with semitransparent ice, like ground glass, that 
admits only a dim half-light from above. 
The banks of coarse wet grass and mud show dimly along 
this strange underworld with the quiet unfrozen water holding its 
still course between them; and here the muskrats are free to come 
and go as they please, and swim, with their heads out of water, 
123 
