350 Life-histories of Northern Animals 



bank west of the house. It proved to be a female, she had the 

 usual teats, but only four in 'commission.' I caught her 

 again in the afternoon in the same place. Each time on being 

 released she took refuge in a hole remote from the nest hole, 

 once twenty-five feet away, once fifty feet away. I have never 

 seen more than one old one about this hole. 



DEN I am not aware that any one has ever watched a Chipmunk 



actually at work burrowing, but circumstantial evidence shows 

 that it adopts an ingenious method of concealing the entrance. 

 Beginning at any convenient point in the selected bank, it 

 drives a long crooked tunnel with an outlet in some thicket or 

 sunny bank. All the earth is carried out and left as a mound 

 at the entrance; when the burrow is finished this over-conspicu- 

 ous hole is permanently closed up. Thus there is little outward 

 sign of the real doorway to the home. The calibre of the bur- 

 row is one and a half to two inches. I do not beheve that 

 the Chipmunk brings earth out in its cheek pouches; these 

 are reserved exclusively for food. 



A curious instance of pertinacity on the part of the species 

 took place at my home, Cos Cob, Conn. A Chipmunk had 

 decided to make a doorway in the middle of the drive. Ac- 

 cordingly the tunnel appeared, bored from below. I filled it up 

 with coarse gravel, and packed it tight for at least a foot down 

 into the burrow. Two days later it was reopened from below. 

 Again it was rammed full of hard gravel, to be opened again, 

 and within forty-eight hours. Sixteen times during one month 

 did I stop up this hole, and as often it was reopened from 

 below. What became of the bushels of gravel I could not find 

 out, but a general depression at that part of the drive began to 

 show. At the end of five weeks' struggle I went away from 

 home, for a rest, the Chipmunk triumphantly completing its 

 earthworks. That was in 1903, and he held it peacefully 

 throughout 1904. 



In 1905 I renewed the attempt. For thirty successive days 

 in the month of May I closed the hole once, or sometimes twice, 

 in a day, and as often it was opened from below. Twice only 



