246 Department of Conservation of Louisiana 



It has been found that wherever muskrats are normally 

 present in the greatest numbers the peaty humus is several 

 feet in thickness. This overlay, which consists of about 

 90 % vegetable matter, consists largely of accumulated dead 

 remains of the sedge and grasses of the region. The Dela- 

 croix Island region has such a humus; a depth of 17 feet 

 has been found in some places. 



This humus layer is of importance to the muskrats in 

 that its food plants intermingle their rooting systems with 

 the decaying vegetation. In it the fur animals dig their 

 dive holes and subways through the soft mass far more 

 easily and faster than if they had to tunnel through clay. 

 We find the peculiar structure of the peaty humus allows 

 these tunnels to remain open without caving; this would 

 not be if the muskrat dug through sand. 



Areas examined with this in mind showed : 



Marshlands with thin layers of peaty humus were de- 

 ficient in muskrats. 



Marshlands where the peaty humus was very thick, the 

 muskrat population proved to be very heavy and a better 

 grade of fur came from the animals taken on such areas. 



It is suggested that those interested in this subject read 

 the chapter on the "Ecology of the Louisiana Muskrat 

 Lands," chapter 25 of this bulletin. 



Habits 



While muskrats are classed as nocturnal mammals, they 

 are frequently seen during the daylight hours, either swim- 

 ing or traveling about. So pronounced are their night- 

 time activities, however, that there is frequently met a trap- 

 per of a score of years' experience in the marsh who has 

 never seen a free live 'rat and his acquaintance with them 

 is confined to the animals he finds in his traps. 



Muskrats, it seems, are subject to migratory fancies, or 

 "fits," as one Acadian trapper expressed it. When animated 

 by this desire, they frequently move in bands, through 

 fields, along and across roads, and are found far from water 

 or usual marshy habitats. When encountered on one of 



