16 BULLETIN OF TEE LABORATORIES 



often used by trappers for the more expensive castoreum in preparing 

 "scent" used in baiting traps. 



As, already indicated, the habits of the muskrat are subject to 

 considerable variation. Its usual home is a long burrow opening be- 

 neath the surface of the water and passing many yards into the bank, 

 terminating in a cosy nest beneath the protecting roots of a tree. It 

 is here that young are reared and from these burrows the entire family 

 may be seen emerging at twilight to engage in swimming races, games 

 of tag, and sportive contests upon the surface of the stream. The 

 head and rudder-like tail alone project above the surface and the long 

 V-like diverging ripples which are created by the rapid swimmer soon 

 span the entire stream and stand out in bold relief as they catch the 

 sky tints at sun set. In regions not frequented by man or sufficiently 

 protected by trees long run-ways may be traced from these burrows 

 into neighboring meadows or wheat-fields. The family is large and the 

 appetite is extensive if not critical. Almost anything of a vegetable 

 nature will be tolerated but the corm-like roots of rushes and the 

 rhizomes of the water-lily as well as flag roots are relished. The fran- 

 tic and grotesque haste with which the rat when disturbed rushes down 

 the run way toward the water, oblivious to any obstacle, is very 

 amusing and sometimes startling and may have given rise to the 

 stories of fierce on-slaughts upon man. Young man-afraid-of-his- 

 shadow might readily consider himself beset as the excited rat comes 

 crashing down his path regardless of everything but his destination. 

 Nevertheless there seems to be considerable evidence that old 

 "rogue'' rats are decidedly irascible, and a worried mother rat may 

 over-step the bounds of etiquette in defence of her young. The bur- 

 rowing habits of the rat associate him with the cray-fish and other 

 enemies of canals and dams. Even in the vicinity of a large city like 

 Cincinnati large numbers are annually taken in the canal-banks for 

 their skins, which, when in prime condition, bring 15 to 18 cents 



The comparatively simple domicile above described is adequate 

 for the southern states and flowing waters but in Wisconsin and Min- 

 nesota the conditions are very different. Nearly every quarter section 

 has its small lake or pond and these pools are shallow and mostly filled 

 with weeds. Here the muskrat finds congeneal resorts Even in the 

 bleak prairies the sloughs and ponds fairly swarm with these furry 

 denizens. Here the intense cold of winter freezes all standing water 

 to a depth of over four feet so that the openings of the summer homes 



