/ ANIMALS OF NORTH AMERICA. 65 # 
All their work is performed in the night ; and they are so 
expeditious that in the course of one night I have known them 
to have collected as much mud as amounted to some thous- 
ands of their little handsful. They cover the outside of their 
houses every fall with fresh mud, and as late in the season as 
possible, which, freezing as hard as a stone, protects them 
from their common enemy the wolverine ; and as they fre- 
quently walk over their work, and sometimes give a flap with 
their tail, particularly when plunging into the water, this 
without doubt has given rise to the vulgar opinion that they 
use their tails as a trowel, with which they plaster their work ; 
for the flapping of the tail is only a habit which they always 
preserve, even when they become tame and domestic, and 
more particularly so when they are startled. 
The animal mostly allied to the beaver is The Muskrat or 
Musquash (Fiber Zibethicus ) . It probably gets its name 
from the musky odor it emits, which even is prevalent in 
the tail long after it is dried. Unlike the beaver, it remains 
without fear at the advance of civilization, and doubtless owes 
its security to its nocturnal habits. Its burrows are very 
injurious to mill-dams and embankments. Bartram says that 
in Carolina, Georgia, and Florida, it is never met with within a 
hundred miles of the coast, showing the care of the Creator in 
not distributing it, where so much depends upon embankments. 
Its favorite food is the calamus , or sweet scented rush, 
the root of which it devours with avidity : it also feeds on the 
fresh-water mussel. Godman denies its being pisciverous, 
but if he had seen the heaps of mussel shells bearing marks 
of teeth accumulated here and there round some flat stones 
just above the water in the lakes of New York state, and 
sundry other northern waters, he would have recalled his 
assertion. It is found all through the temperate portions 
of this continent, and is peculiar to it. According to Dr. 
Richardson, from four to five hundred thousand of its skins 
are annually exported to England, principally to be used in 
the manufacture of hats. E 
