The Fur Animals of Louisiana 287 



"These pelts were average lots, containing kits, medium and adults. 

 There were several cases where kits had 9 mammae and we have 

 iound mice with 10, so that the number does not depend upon the age 

 of the muskrat. 



"Amputated legs do not hinder muskrats from breeding. It is in- 

 teresting to note that upon every occasion when mating was observed, 

 the muskrats were partially submerged in water. Before mating, the 

 males and females were both observed to back up against the sides 

 of the pen, leaving an intense odor of musk. This evidently serves as 

 -a sign of possession or recognition. We have often noticed these 

 musk-places in the marsh, especially during the winter and spring. 



ENEMIES 



"Although injudicious trapping is the greatest enemy of the musk- 

 rat, yet there are several animals which include the rat in their diet. 

 The fact that the muskrat is most suspicious and either stays under 

 cover or else very near it, is a great help in eluding animals of prey. 

 Alligators are, perhaps, the muskrats' worst natural enemy, but they 

 have been hunted so extensively during the last few years that they 

 Are becoming scarcer and scarcer. Large moccasin snakes have been 

 found to eat young muskrats and they are also capable of entering 

 the houses through the plunge holes. Some evidence of owls taking 

 mice and small kits has been obtained. No direct evidence of hawks 

 killing rats has been found, but trappers insist that they tear the 

 pelts of many rats caught in traps. Minks have been known to kill 

 and eat muskrats. 



"Like the Maryland muskrat, this species is also infested by a mite 

 which has been identified by Dr. Ewing of the Smithsonian as Tetra- 

 gonysus spiniger. Some rats have more than others and even mice 

 in the nests have been found infested with them. However, they seem 

 to cause but little discomfort. 



"Surprisingly few endo -parasites have been found so far. Out of 

 ten muskrat specimens sent to Dr. Ward of the University of Illinois, 

 none contained endo -parasites. One specimen, sent to Dr. Manter, 

 now at the University of Nebraska, proved to be a degenerate arachnid. 

 The damage done by endo-parasites is evidently neglible. As for dis- 

 eases, none has been found so far. 



"Of all the climatic conditions which are detrimental to muskrats, 

 drought seems to be the worst. This not only decreases the amount 

 of available water in the marsh, but also affects the vegetation, thus 

 decreasing the amount of rat food. Marsh fires, when set during dry 

 weather, when the water on the marsh is low, are also detrimental. 

 This not only burns the vegetation, thus destroying food and cover, 

 but also destroys many hills and even the rats themselves. How- 

 ever, judicial firing has been witnessed after a heavy rain, when the 

 marshes were quite wet, and no damage was done. The high water pre- 

 vented the roots of the plants from being burned and the houses were 

 too wet to be destroyed. 



"After the hurricane of August 28, 1926, the water was very high 

 over the marshes in the Penchant region. A survey proved that it 

 had not damaged the rat land at all. The rats, in fact, were more 

 active than ever, building their houses higher and digging for roots. 

 The recent storm and resulting very high water has also had no detri- 

 mental effects in this region." 



