DOMESTIC RATS AND MICE 41 



mothers, or mice which are out of condition, but are too 

 fattening for general use. 



Bread and milk is an excellent food for mice, particularly 

 mothers and newly weaned youngsters. Boiled rice and 

 cereals are a welcome change, but must not be given too 

 freely because of their fattening qualities. Such foods are 

 best fed at night, when the mice are most active. All that 

 remains should be removed in the morning, as it quickly 

 sours. 



Small pieces of raw or boiled potatoes, carrots and simi- 

 lar vegetables are relished by mice. Green food should 

 be supplied in the form of lettuce, chickweed, dandelion, 

 etc. Such food is of the greatest importance in keeping 

 mice in health. 



Clean water should be in the cages at all times, even when 

 soft and green foods are being fed abundantly. 



A pair of mice will do very well together, but many 

 breeders make a point of running two does with each buck. 

 When babies are expected, the does should be removed to 

 separate cages. Here they should be furnished a secluded 

 retreat, well provided with soft nesting material. A little 

 extra food at this time is very beneficial. The period of 

 gestation in mice is about twenty-one days. 



When the young finally appear, they should not be dis- 

 turbed for a few days. Then they may be examined quietly. 

 If a few mice are being kept merely as pets, or if certain 

 lines of investigation are Ijping followed, the entire litter 

 may be left. But if it is desired to improve the size and 

 stamina of the strain, not more than four or five babies 

 should be left with the mother. If the mice are of a marked 

 variety, the poorer specimens can be detected at an early 

 age and destroyed. Among selfs, the choice may be more 

 difficult, but there are always some faults, however small, 

 for which their possessor may be discarded. The little 



