64 ANIMAL COMPETITORS 



there are many inexpensive methods for pre- 

 venting this increase. The destruction of rank 

 grasses and weeds along fences and ditches, 

 and particularly, in the West, the pasturing off 

 of the last growth of alfalfa in fall, thus ex- 

 posing the mice to the sight of predaceous en- 

 emies, are important. Winter-burning of dry 

 vegetation on wild hay lands, on strips border- 

 ing fields, and on swampy or otherwise waste 

 areas in and about cultivated fields, will aid 

 materially in controlling them. The survivors 

 may invade cultivated fields, but there they can 

 be more readily poisoned. Flooding the fields 

 in cold winter weather, when the mice quickly 

 perish from exposure, is an effective method 

 in irrigated lands. Plows turn out the bur- 

 rows and nests of practically all the mice pres- 

 ent and render them easy victims for dogs, 

 which when trained to kill mice can not be too 

 highly recommended as effective and inexpen- 

 sive aids in controlling the pests. That hawks, 

 owls, gulls, crows, ravens, and herons among 

 birds, and skunks, weasels, foxes, and badgers 

 among mammals, are persistent enemies of 

 field-mice and other rodent pests has been often 



