Nature Bulletin No. 537   September 27, 1958
Forest Preserve District of Cook County
Daniel Ryan, President
Roberts Mann, Conservation Editor
David H. Thompson, Senior Naturalist

****:THE MUSKRAT -- LITTLE BROTHER OF THE BEAVER

In the Algonquian Indian languages he was called Musquash. The 
Hurons called him Ondatra and that hag now been adopted as his 
scientific name. But the best Indian name of all meant "little brother of 
the beaver". He gnaws like a beaver, swims like a beaver, builds houses 
like a beaver, and looks like a little beaver. He call him Muskrat 
because, also like the beaver, he has a pair of musk glands used to leave 
messages for others of his kind.

This is the most important fur bearer to professional trappers and the 
American fur industry. More than any other wild animal, the muskrat 
converts millions of acres of cattail marshes and weedy shores into a 
crop of fur and flesh. To the farm boy with a few traps it means money 
in the pocket and experience in the skills of outdoor life. Our 
womenfolk prize rich warm coats of Hudson seal, the trade name for 
muskrat fur. The dark red meat has a wild game flavor but, because the 
word "rat" is unpleasantly suggestive, muskrats appear on menus under 
such names as Marsh Rabbit and Maryland Terrapin.

Sometimes these animals become a pest, raiding corn fields and other 
farm crops near the water's edge, but they do the most damage to 
earthen dams, dikes, levees and canal barks which are occasionally 
destroyed through leaks started by their burrows. In our Cook County 
forest preserves, however, the muskrat plays a star role in establishing 
and maintaining natural landscapes and a natural balance among the 
wildlife of almost a hundred bodies of water which have been created or 
restored during the past thirty years. Neither they nor any other wild 
animal may be hunted or trapped in any of the preserves.

In cattail marshes and other shallow weedy waters, muskrats pile up 
great heaps of aquatic plants to build a house or lodge that has, inside, a 
warm living room reached by an underwater entrance. From this home 
they range out to feed on the succulent roots and stems of such plants, 
even under thick ice in winter. However, in streams, farm ditches, and 
in many ponds and lakes -- especially during summer -- muskrats live in 
burrows dug deep in the banks. Those burrows start beneath the surface 
and slant upward to an enlarged chamber above the water level.

The muskrat is a thickset short-legged animal with a foot-long body 
about the size of a small cat. The adults average two pounds in weight 
but, rarely, reach four. It has a 10-inch black scaly tail which is 
flattened vertically -- unlike the broad paddle-like tail of a beaver. This 
tail is used as a rudder, or to scull slowly, or to smack the water as a 
danger signal. The fur is dark brown on its back, with very thick 
waterproof underfur and long reddish-brown guard hairs that glisten.

The "rat" has small beady eyes and ears which are nearly hidden in the 
dense fur. The hind feet are large, webbed between the toes, and used 
like the flippers worn by skin divers. While swimming, the small 
forepaws are folded underneath the chin. Like all rodents, it has a pair 
of chisel-teeth or incisors above and below, separated from the grinding 
teeth or molars by a gap, and its lips can be closed behind the chisel-
teeth to keep water out of the mouth while gnawing beneath the surface.

A muskrat is clumsy and glow on land, seldom venturing away from 
water in daytime, but it is a courageous scrapper when attacked or 
cornered. Next to trappers, its greatest enemy is the mink which raids 
muskrat houses and burrows to eat their young.

In trappers' language they are "mushrats" or just plain "rats".