148 MORE MINOR HORRORS 



who made the following experiment : He 

 placed the carcasses of two or three horses 

 in an enclosure, which permitted the entrance 

 of rats by certain known and closable paths. 

 Towards midnight, he and some workmen 

 entered the enclosure, closed the rat-holes, 

 and in the course of that night killed 2650 

 rats. He repeated the experiment, and by 

 the end of four days had killed 9101 rats, 

 and by the end of a month 16,050 rats. During 

 the process of these experiments other car- 

 casses were exposed in the neighbourhood, 

 so that in all probability M. Dusaussois 

 attracted to his enclosure but a small pro- 

 portion of the total available number of 

 rats. All around this slaughter-house the 

 country was riddled with extensive burrows, 

 so that the earth was constantly falling in. In 

 one place the rodents had formed a pathway, 

 500 yards long, leading to a distant burrow. 



A rat census can never be taken ; but, 

 estimating that there is one rat for every human 

 being on these islands, or less than one rat 

 for every acre of ground, a moderate estimate 

 would give us 40,000,000 rats at any one time. 

 It has been calculated that a rat does at least 

 7.S. 6d. worth of damage during the course of 

 the year : hence in Great Britain and Ireland, 

 we may annually charge them with a loss of at 

 least £15.000,000 ! 



