BRITISH MAMMALS 



three months old. It has been computed that, if three 

 litters of ten each were produced every year, a pair of 

 Brown Rats would, at the eleventh generation, due at the 

 commencement of the fourth year, number no less than 

 one hundred millions ! Fortunately, the Rat has several 

 natural enemies, which help to keep its numbers in 

 check. Otherwise our country would be over-run with 

 them, with results little short of disaster. The young of 

 the Black Rat are bora bhnd, but at the age of sixteen 

 days their eyes open. It is curious to reflect that, when 

 kept in captivity, the parents will often eat their own 

 progeny, and that the young are more savage and less 

 docile than their parents, which have probably become 

 reconciled to their cage life as pets. 



Brown Rat. — Whilst this common species (Fig. 12) 

 is resident both in town and country, and around farm- 

 steads, granaries, corn stacks, and the like, where it 

 commits great havoc, it is probable that if its numbers 

 could be reduced to a minimum in large towns and cities, 

 its carrying powers of disease germs would be less acute. 

 It seems that London is the greatest sinner in housing 

 such a plethora of Rats in its warehouses, sewers, base- 

 ments, cellars, Thames-side, and other places, and we 

 are told by eye-witnesses that, when there has been a fire, 

 whole hordes of these rodents have been seen leaving the 

 building in a body, terrified of the calamity that had 

 befallen them. Both wild and domestic animals have a 

 great dread of fire, especially dogs and horses. As 



showing how Rats infest corn stacks, one or two of these 

 66 



