MICE AND VOLES. 131 



Most of llie other iiesli-eating birds do too much damage to 

 useful birds to deserve protection. 



3. llonedial Measures. 



Remedial measures against mice may be with or without 

 poison. The chief rule is to adopt measures every year which 

 suit the localit}^ so as to prevent as far as possible any extra- 

 ordinary increase in the number of mice and voles. According 

 to trustworthy observation, there are far more females than 

 males in the spring, and mice should therefore be destroyed 

 as much as possible in February and March. Private enter- 

 prise, especially in forests where it is difficult to get at the 

 mice, is not sufficient for this purpose, but the State must 

 direct matters and induce private persons to assist in the 

 energetic destruction of mice both in fields and in forest, which 

 will be to the public advantage. 



a. PUfaHs. 



Trenches must be dug in the ground, and visited daily to 

 keep them clear from leaves, etc., and to remove and kill the 

 captives. They should be 8 — 10 inches wide, and 1'2 — 16 

 inches deep, with vertical smooth walls. The base of the 

 pitfall must be beaten hard, and glazed earthenware vessels, 

 or drain-pipes, one every 3 or 4 yards, buried level with the 

 bottom of the pitfall. A few grains of wheat act as lures for 

 the mice, and those which are found in the pitfall are killed 

 with a pointed piece of coarse iron wire ; they will die other- 

 wise of starvation. Such trenches are to be recommended 

 against field-mice along the borders of fields and forests, and 

 around forest nurseries and seed-granaries. In Mecklenburg, 

 10,800 mice were thus destroyed in autumn, 1872, between a 

 clover field and a sown plantation. 



b. Traps. 



Traps are useful, especially against water-rats and bank- 

 voles, and various kinds of devices may be used to trap mice 

 according to species and local circumstances. 



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