4 McAtee — Mammals, Reptiles and Batrachians of Indiana. 



7. Mus musculus Linn. 



HOUSE MOUSE. 



Abundant near and in the dwellings of man, and also tlioioujihly estal)- 

 lished in many oirhards and fields. From one nest in a field thirteen 

 house mice were taken in the month of October. They were practically 

 hairless when captured and their eyes were not yet ojien, but they were 

 raised by feeding tliem milk with a pipette. They became perfectly tame 

 and fearless and tliis hastened tlie end of all, as tliey ])ers^isted in leaving 

 the cage and getting under someone's feet or a door. One killed on Feb- 

 ruary 18, following, was apparently sexually mature. 



An adult taken April 8, 1903, had a well marked gray spot on the fore- 

 head. 



8. Mus norvegicus Erxleben. 



HOUSE RAT. 



Abundant. 



9. Peromyscus leucopus (Rafinesque). 



DEER MOUSE. 



Abundant. Commonly their homes are in the rock slides or under logs 

 and isolated stones and every wooded ravine is alive with them. They 

 also live along fence rows and even in the open meadows and fields, but 

 are rarer here than in the woods. Many of them occur in the caves, even 

 at a considerable distance from the mouth. 



These cave dwellers usually have a somewhat different appearance from 

 their above-ground brethren, being more pop-eyed and having apparently 

 larger ears and longer wh-iskers. This may be due to all mice in caves 

 partaking of these particular variations, while in terrestrial specimens, 

 some show them and others do not, the effect thus being lost. Certainly 

 I have measured surface deer mice that had vibrissae and ears of equal or 

 even greater length than specimens from caves. 



As deer mice are often said to be strictly nocturnal, some observations 

 tending to show that this conclusion is not strictly true may be of interest. 

 They are at least occasionally seen abroad by day. One afternoon in 

 October, I surprised one near a spring at some distance from its burrow, 

 which it hurriedly sought. I have also seen them running about barn- 

 yards near woods in the early morning, and once found one feeding on a 

 hillside at high noon. Near Washington, D. C, I have several times seen 

 them scamper from one burrow to another in tlie day time, and Dr. A. K. 

 Fishe.' as well as the writer, has surprised tliem rummaging about shelves 

 of a cabin by day. In captivity at all events, they do not cease activity 

 on account of daylight. 



It has been said tliat this species is not at all carnivorous, but there is 

 some evidence to tiie contrary. Many sj)ecimens are gnawed in the trai)s 

 and this is probably not all due to Blaviua, and certainly is not in the 

 caves where the shrew has not been taken. Furthermore, suet makes an 

 excellent bait, and I have fed caged deer mice with raw meat. Two, con- 



