NOTES ON THE MAMMALS OF LAKE MAXINKUCKEE 23 



have on more than one occasion found partly devoured fish at their 

 feeding stations, and remains of fish, frogs and crustaceans in their 

 kitchenmiddens. We have never seen a Muskrat catch a live fish, 

 but have no doubt they do so. They certainly pick up freshly 

 dead fish which they chance to find. 



At Lake Maxinkuckee the Muskrats raise at least two litters, and 

 probably three, each season. About the middle of June, 1901, 

 young muskrats about half-grown were seen swimming about or 

 sitting on their haunches on shore eating bits of lily roots. These 

 were probably of the first litter. On June 15, 1903, a nest with 5 

 young was found in a pile of brush on marshy ground on Long 

 Point. The young were evidently not more than a few days old, 

 as their eyes were not yet open. On May 31, 1901, we caught one 

 about one-third or one-half grown on south shore of lake. Septem- 

 ber 5, 1906, saw 2 young not more than half grown. On another 

 occasion, a young one was seen on the shore near the Culver depot 

 pier and was almost caught before it took alarm. On another 

 occasion, a young one was seen to dive in shallow water south of 

 Green's pier. Upon wading out to where it dived a hole was seen 

 in the bottom, out of which the Muskrat soon came and was cap- 

 tured. From these data it is evident that at least 2 litters per sea- 

 son are raised in this vicinity. 



In the early winter, after ice has formed some distance out from 

 shore, Muskrats are often seen swimming under the ice. They 

 move along quite rapidly, and present a peculiar appearance, a 

 bubble of air at each nostril expanding and contracting as they 

 breathe, and a number of small bubbles on the fur giving them a 

 silvery color. Apparently the Muskrat before diving fills its lungs 

 with air, portions of which it exhales and rebreathes again. During 

 the time it remains as a bubble at each nostril it is purified through 

 its contact with the water and rendered fit for breathing again. 

 This peculiar habit would seem to account for the ability of the 

 Muskrat to remain under water so long. On one occasion (in De- 

 cember, 1904) when standing on the ice a peculiar sound was heard 

 beneath our feet. Upon investigation it was found to be caused 

 by a Muskrat gnawing at the under side of the ice. The sound 

 was like that made by a rat gnawing under a floor. 



