THE STACKYARD POPULATION 403 



escaping mice. If there is a considerable flock of farmyard 

 hens, not a mouse will escape. They seem to be filled with 

 a killing fury, and they kill with astonishing precision. One 

 peck is usually enough to kill the mouse, which is a curiously 

 tender animal in some respects. Most of the hens are con- 

 tent with killing ; but a certain number attempt to eat the mice, 

 usually suffering severely if the attempt is at all successful. 

 The spectacle is thoroughly repulsive ; and it is difficult to 

 account for this instinct in hens. Mice are certainly not their 



FIELD-MOUSE 



natural food ; and though hens in winter have a certain crav- 

 ing for animal food, the mouse Is not the form in which they 

 might be expected to take it. They are usually punished for 

 their unnatural craving by a fit of sickness. But the hens are 

 more eager to kill than animals to whom the mice is proper 

 prey. One has seen a cat sitting utterly regardless of the 

 escaping mice, which were pursued a outrance by the hens. 



It is comparatively easy to clear a standing stack of rats. 

 It is impossible to clear out the mice. The rats make runs 

 within the stack from floor to roof. If ferrets are put into a 

 stack, you will as a rule first see the rats appear on the very 

 roof or high up in the stack. A common method of destroy- 



