I0 g ZOOLOGICAL SKETCHES. 



by any voluntary motion, unless you know their haunts 

 and keep your eye on their holes. There they sit, 

 tail and hind-legs tucked out of sight, their fore-feet 

 close together, every muscle braced for an immediate 

 sally, yet rigidly motionless as long as there are any 

 boys or dogs in sight. But watch them from behind a 

 closed window or from a perch on the cotton-bales : the 

 moment the road is free, the end of the sharp nose begins 

 to work, the hind-legs become visible, and with a sudden 

 rush, in a perfect bee-line, the rat is across the street and 

 into his subterranean hunting-grounds, perhaps the vault 

 of a bonded warehouse that has lately received a con- 

 signment of New-Orleans molasses. 



Rats do not like to cross an open street, and mice 

 avoid the centre of the floor if they can possibly reach 

 their objective points by running along the walls : instinct 

 seems to tell them that alongside of a vertical surface 

 the visibility of a body cannot be aggravated by its 

 shadow. They also seem to know that monotonously 

 repeated sounds are least liable to attract attention : the 

 steady gnawing of a wall-mouse " blends with silence" 

 as readily as the ticking of a clock. Co-operative mice 

 keep time: at the end of an interesting chapter I have 

 often become conscious of the fact that a rodent com- 

 mittee of ways and means were rasping away vigorously 

 in my immediate neighborhood and had evidently been 

 hard at work for some time. I have two such partners 

 in my bedroom, and in sleepless nights I sometimes enjoy 



