292 THE GRAY RAT. 



over the country in a wave of settlement. This 

 is because any move of individual rats quickly 

 becomes a general move ; and the greater the 

 number that settle in one locality, the greater is the 

 number of the scent-trails leading to that locality, 

 and the stronger do these scent-trails become, till 

 finally the drift may assume the form of a migra- 

 tion, the rodents moving in shoals from their 

 original feeding-ground to one of greater promise. 



It is highly improbable that one rat, finding a 

 paradise of plenty, dutifully returns to inform his 

 neighbours of the fact. Such a feat is not in 

 accordance with the gray rat's disposition, and 

 were he able to retain undivided possession of the 

 new territory, he would readily do so. Reference 

 has been made to the extraordinary hearing-powers 

 of the weasel, and to how this power is exercised 

 in its hunting. There is no doubt whatever that a 

 weasel can tell from a very great distance whether 

 or not the barn on the skyline is infested by rats, 

 and in all probability the rats themselves possess 

 the same power. In most country districts the 

 barns where food-stuffs for horses or cattle are 

 stored are often a considerable distance apart, and 

 in the part of Scotland where the writer lives it is 

 no uncommon thing for a barn to be located at the 

 edge of moorland country a mile or more from any 

 other building, and in the midst of a region where 

 buildings of any kind are so remotely scattered that 

 one can view vast tracts of country without a human 

 structure in sight. Yet the rats find their way to 

 each and every one of these barns where there is 

 food to draw them, and, during the warm months 

 at any rate, every barn has its full complement 

 of rats. It is particularly noticeable, however, that 

 the buildings near water, even though it be the 



