BEHAVIOR OF WHITE RATS IN PRESENCE OF CATS 27 



in the same way. There is an absolute cessation of activities 

 indicative of either tendency for as long as an hour. The inhi- 

 bition of the mothering activities has been indicated above. 

 After repeated experiment, the mother of the very young no 

 longer left the nest but crouched in a frightened manner over 

 them. This was in no sense protective, but rather identical with 

 the attitudinizing pf the other individuals under similar circum- 

 stances. Just as striking, was the arousal of the rats from sleep. 

 Forty-one seconds after a cat had been placed upon a cage of 

 sleeping rats, disturbance began. The first indication was the 

 opening of the eyes and the raising of the nostrils in an explora- 

 tory manner. Two minutes later all the rats were huddled in a 

 corner of the cage; one was whimpering. In a few seconds, the 

 rats in an adjoining cage were behaving in the same way. 



Associations are established very rapidly with these activities. 

 It was noticed as the experiments proceeded that they were car- 

 ried over to objects originally arousing no such behavior. For 

 some days after a two-weeks experimental session with a two- 

 months-old group, a partial response was excited by the presence 

 of the experimenter himself, or by objects placed upon the cages. 

 With one group of young rats attempts had frequently been made 

 to fed them bits of cheese during the presence of a cat. For 

 several days after the series was over fresh cheese repeatedly ex- 

 cited a marked disturbance. This was especially true when the 

 presentation of the cheese was accompanied by a clucking sound 

 frequently made on other occasions to attract the attention of 

 the rats. The establishment of such associations is quite il- 

 luminating hi view of the work already done on "conditioned" 

 and " unconditioned reflexes." 



To conclude : the experiments here reported demonstrate that 

 there is a specific factor, probably olfactory, about the living cat 

 which induces in white rats of two weeks and older a marked 

 bodily state which is suggestive of fear. 7 This state can be 



7 We have found that, in some subjects, this fear-attitude is more like Preyer's 

 cataplexy than like the timidity or cowering observed by Yerkes (Yerkes, R. 

 M., The heredity of savageness and wildness in rats, J. of Animal Behav., 1913, 

 3, 287 ff.). Since the classical descriptions of cataplexy and of "hypnotized 



