FiGTJBE 11. — Entrances to "pipe lead" tunnels at three levels in bank of tidal river, 

 Maryland — at low^ tide. 



age ditches often do not build 

 houses, but burrow into the stream 

 banks. Entrances to these burrows 

 are usually under water most of the 

 year. A burrow may have several 

 entrances at varying depths built at 

 different times to meet changing 

 water levels (fig. 11). The tunnels 

 lead back into a main burrow and 

 then upward into one or more large 

 nesting chambers which are well 

 above water level. The larger bur- 

 rows may have well-hidden surface 

 openings that are kept loosely 

 plugged and undoubtedly function 

 as air vents. 



The muskrat's habit of burrow- 

 ing into dams, levees, canal banks, 

 and other embankments to build its 

 home often leads to serious dam- 

 age — to the structure itself and to 

 adjacent agricultural lands by flood- 

 ing them or by draining waters from 

 irrigated crops. Levees and dikes 

 in rice fields of the South, in west- 

 ern irrigation projects, and in fish 

 hatcheries are especially vulnerable 

 to the burrowing activities of the 

 muskrat. Muskrats often under- 

 mine shelled corduroy roads in the 



marsh country, making travel haz- 

 ardous at times and road mainte- 

 nance a constant expense. 



Control of destructive muskrats 

 must be in accordance with local 

 regulations; the State conservation 

 department should be consulted by 

 the landowner before he attempts to 

 remove the offending animals. Re- 

 moval usually is by trapping, shoot- 

 ing, or digging the muskrats out of 

 their burrows. 



Food of the muskrat 



The diet of the muskrat varies 

 with the season and the plants avail- 

 able. Chiefly herbivorous, in some 

 localities the muskrats may feed to 

 a limited extent on crayfish, crabs, 

 mussels, snails, minnows, and slug- 

 gish fish. These items are thought, 

 however, to constitute a relatively 

 minor and seasonal phase of their 

 diet. 



The muskrat's food is varied in 

 summer, consisting of leaves and 

 roots of many aquatics, such as the 

 cattails, wildrice, arrowhead or 

 duck potato, waterlily, marshaster 

 {Boltonia asteroides), pond weeds 

 {Potamogeton spp.), waterweeds 



8 



