FOREST PROTECTION 17 



III. MICE. 



a. Damage done. 



The mice live on buds, seeds, seedlings and the cambium layers 

 of seedlings. 



The field mice undermine the ground in nurseries and planta- 

 tions following the rows of plants and cutting the roots about 

 one inch below the surface of the ground. Frequently they 

 seem to follow in mole mines. The damage done by gnawing 

 is conspicuous in plantations of locust and black cherry. In 

 seed plantations on abandoned fields at Biltmore, mice have 

 done enormous damage to oaks and hickories. Planted locusts 

 are bitten-off below ground. In the Biltmore nurseries, oak 

 seed beds have suffered severely by the mice cutting the roots. 

 Transplanted white pines were severely decimated, by gird- 

 ling, in February, 1909. 



b. Protective measures. 



Avoid autumn sowing. ' 



Plant seeds broadcast instead of planting in rills. 

 Have nurseries far from grain fields and from abandoned fields. 

 Keep deep and clean pathways between the beds. Surround 

 nurseries by deep and steep- walled trenches. Insert pit falls 

 in the bottom of such trenches. Work the nurseries contin- 

 uously. Do not cover the nurseries with mould or moss form- 

 ing hiding places. 



Keep the sedge grasses and weeds down in nurseries and re- 

 generations, possibly by pasturing with cattle and sheep, thus 

 disturbing the mice and tramping down their mines. Burn 

 abandoned fields before planting. 



Pigs admitted to the woods just before a seed year destroy 

 the mice whilst preparing the soil for natural regeneration. 

 Protect the mouse-eaters, especially those which are fond of 

 voles as owls, crows, fox, o'possum, cats. 



c. Remedial Measures. 



Kill the mice by trapping or poisoning. In this latter case, 

 place grains of wheat poisoned by immersion in strychnine, 

 arsenic or phosphorus into drain pipes so as to check the possi- 

 bility of accidentally poisoning singing birds or quail at the 

 same time. Comp. Farmers bulletin No. 369, Biological Survey. 

 The root of certain Scylla species, chopped into sausages, kills 

 the mice by causing their bladders to burst. Gypsum is said 

 to have a similar effect, solidifying in the stomach. The lat- 

 ter remedies are not injurious to the mouse-eating animals 

 which are frequently poisoned by catching the poisoned mice. 

 The vaccination of the mice with the so-called "typhoid dis- 

 ease" has not been sufficiently successful so far. 



