278 Department of Conservation of Louisiana 



these were the more important matters to be learned of this 

 very prolific mammal of the south Louisiana marshlands. 



In spite of his opportunities and length of employment, 

 Mr. Svihla did not accomplish all of the work mapped out 

 for him and his services were terminated in the summer of 

 1927. In the course of his field work the biologist learned 

 a number of facts of interest, if not of any great impor- 

 tance, as to some of the habits and life of our muskrat, 

 and the matter that follows is an abstract of the report 

 that he made the department at the conclusion of his em- 

 ployment : 



"The Louisiana muskrat, due, no doubt, to constant persecution, 

 has an intelligence and cunning, which, if accounts in literature be 

 true, far exceeds that of his northern brother. He has a certain 

 cautiousness in approaching traps which has often proved his salva- 

 tion. During cold, still nights, muskrats work industriously, building 

 on their houses, digging runways, and searching for palatable bits of 

 food. A very windy night or warm weather results in little activity 

 in the marsh. During the summer months, when the weather is hot 

 and dry, signs in the marsh and also in pens where 'rats are known 

 to be, are exceedingly scarce. Plenty of water and cool weather are 

 the most favorable factors for muskrat activity. They are quite 

 adaptable, however. Extremely high tides do not trouble them, and 

 in the summertime when the marsh is dry and the days very hot, 

 they often plug up the surface holes of their runways, thus retaining 

 the coolness and moisture within. In all the southern marsh districts 

 these muskrats live entirely in the marsh proper. There they build 

 their houses and runways and raise their young. They are never found 

 in the bayou banks. 



"The muskrat is a social animal in the sense that it likes company 

 of its own kind. In several places in the marsh we have built pens 

 of wire netting wherein pairs of rats are kept. By placing live traps 

 alongside these pens, we have caught a surprising number, consider- 

 ing the extreme scarcity of signs in the adjoining marsh. In one pen 

 a pair of rats was placed and after several days, caught again. To 

 our surprise, not only the original pair was captured, but three addi- 

 tional adult rats. They had evidently climbed up over the two-ioot 

 wire with a foot overhang, and, having gotten in, were unable to get 

 out. 



"We have had three-legged rats escape from a wire pen two feet 

 high with a six-inch band of galvanized iron along the top. Rats have 

 also escaped from pens two and one-half feet high with a foot over- 

 hang. They will often jump when it is impossible to climb. They 

 have been observed to balance on the edge of their water pans on their 

 hind legs, and when stretching was of no avail, have jumped up onto 

 the overhang and scrambled over. 



'"That water is the muskrat's natural element is evidenced by the 

 speed and grace with which it swims, not only in and under water, but 

 also when partially submerged. Rp.ts have often been observed swim- 

 ming under water, and only a slight ripple on the surface indicated 

 where the rat was. When frightened, a muskrat will plunge into the 

 nearest water immediately with a startling splash, and the ripples from 



