POISONING MICE 427 



of their large incisor teeth are plainly visible. The finer markings 

 of the small teeth of the mice can be seen in the wood from which 

 they have removed the bark. As said before, they gnaw near or 

 below the surface of the ground. 



Mounding Injured Trees. A tree of some size, badly injured 

 by field mice, may frequently be saved, if the inner layer of bark 

 has not been destroyed or seriously injured, by keeping a mound 

 of earth over the injury until new bark is formed. 



Protection Against Field Mice. If the area is a small one, 

 recourse may be had to small, inexpensive mouse-traps, such as 

 sell for five cents each or less. A very good method of baiting 

 these traps is to smear the pan with bacon fat and then dust 

 it with oatmeal. 



Early mulching of fruit trees should be avoided. Mulching 

 should be done after the beginning of cold weather, if at all. Cover 

 crops, such as buckwheat, oats, and clover, and trash of any kind 

 harbor mice and render injury likely. An orchard in sod is more 

 likely to be injured than a cultivated one. 



The snow about the fruit trees should be tramped down occa- 

 sionally during the winter to keep the mice from working under it. 



Guards Against Mice. Mechanical guards of approved pat- 

 tern for use around trees are absolutely reliable. These are de- 

 scribed under control of rabbits. 



Washes to keep off Mice. An application of a thick white- 

 wash is a fair repellent for mice as well as rabbits. It is made 

 by slaking quicklime in water, and rendered a deep blue by the 

 addition of bluestone solution. It should be applied late in the 

 fall, and the application should be repeated if possible on some 

 warm day in winter, for the mixture should dry on the tree, not 

 freeze on. To be effective against mice, it should be applied 

 liberally to the trunk close to the ground. A brush or a spray 

 pump with a nozzle adapted for whitewash can be used. Spraying 

 the material in this way is preferable in treating shrubbery and 

 rows of nursery trees. It is more rapid and perhaps more thorough 

 work. It must be borne in mind that after rain and weather have 

 removed these washes from the trunks of trees the bark is again 

 attractive to mice and rabbits. 



Washes containing blood or grease should not be used upon 

 trees, as these are attractive to mice. 



Poisoning mice is probably the most effective way of ridding 

 a field of them, but care should be taken to prevent birds, poultry, 



