BEHAVIOE OF WHITE BATS IN PEESENCE OF CATS 23 



stale cheese, syrups of various fruits, heliotrope, camphor, 

 hydrochloric acid, nitric acid, and a variety of other volatile 

 substances, induced much " prying curiosity," the rats following 

 the odor as it moved back and forth below the front part of the 

 cage. This was the case even when a cloth model of a cat was 

 placed upon the cage in order to simulate the conditions pre- 

 viously established. There was no sign of fear of mice or Norway 

 rats, nor of any part of them, the mice being attacked and in 

 some cases eaten. 



There was never anything about the behavior of the rats that 

 would indicate movements of offense or defense. The entire 

 inhibition of exploratory movements has already been mentioned. 

 The behavior reminds one of nothing so much as a sort of paralysis 

 or at least a kind of inertness, possibly the attitude an animal 

 might take when fascinated. One four-weeks-old male was 

 exploring the top of a nest-box when a cat was introduced. The 

 rat immediately "froze" and hung for twenty-two minutes, one 

 toe after another slipping loose, until finally the rat dropped to 

 the floor where it remained on its back and side. The rats made 

 no attempt to resist the experimenter's hand during the per- 

 sistence of the odor, and, when replaced in the nest, they rested 

 where and in the position they happened to be when set down. 

 The time during which this behavior lasts is striking. As soon 

 as the cats were removed from the observation-frame, the air 

 was changed by currents as rapidly as possible; but the return of 

 the rats to normal movements was very slow. This return, 

 which begins within an hour after the experiment, is marked by 

 half-hearted efforts at cleaning the face or sometimes by a very 

 cautious exploratory movement. Attempts to attract the 

 attention of the rats during this period were futile. The whole 

 organism seemed set in another direction. If, however, they are 

 handled gently for some time, the period of recovery is much 

 shortened. We now come to the questions proposed. 



1. It is evident from the foregoing descriptions that the 

 presence of a cat is a definite occasion for the arousal in the white 

 rat of a characteristic cessation of normal movements and 

 activities as measured by the maintenance of a specific posture, 



