THE MOUSE TRIBE. I4I 



body (8 to 9 inches), and usually not exceeding that of the body alone. The colour 

 of the upper-parts is usually greyish brown, while the under surface is white ; but 

 black varieties are often met with, which in Ireland have been regarded as indicat- 

 ing a distinct species. 



The brown rat is a far more powerful animal than the black 

 species, which has not a chance against its stronger rival, although 

 curiously enough it is stated that on some ships the two kinds may be found 

 living together. The following anecdote, related by the late Mr. Frank Buckland, 

 illustrates in a striking manner the superior power and at the same time the 

 extreme ferocity of the brown rat. " A London rat-catcher," writes the narrator, 

 "shut up together in a cage the result of his day's work, consisting of several 

 dozen rats, of both species, and put them away carefully for the night, their 

 intended fate being to afford sport for his employer's dogs the next morning. 

 What was his astonishment when he came to fetch them, to find none but brown 

 rats remaining ! these cannibals having cruelly devoured all their sable brethren." 



Rats are practically omnivorous in their diet, devouring every kind of human 

 food with avidity, and inflicting untold damage on the hen-roost, the dove-cot, and 

 the rabbit-warren. Their devastations to corn -ricks, or to grain stored in 

 insufficiently protected granaries, are too well known to need more than passing 

 mention. Not only will they, as in the instance recorded above, prey on their 

 cousin the black rat, but they will likewise slay and devour members of their own 

 kind which have been caught in traps or otherwise disabled. In robbing poultry- 

 houses, it is a well-ascertained fact that rats will convey the eggs in an unbroken 

 condition for considerable distances, although it is not yet ascertained how this 

 difficult feat is accomplished. The partiality of these animals for fish is well 

 known, but that they will occasionally catch young eels for themselves has been only 

 recently discovered. Mr. Harting adds that snails both land and fresh-water 

 also form a portion of their diet ; while on the sea-coast they will eat prawns and 

 other crustaceans. 



The prolific nature of the brown rat is little short of marvellous, and 

 thoroughly accounts for its enormous numbers when in favourable situations. 

 Several litters are produced annually, each of which generally contains from eight 

 to ten, and sometimes as many as twelve or fourteen young ; and a female rat will 

 breed when only half -grown, although the number of its progeny is then but three 

 or four at a birth. When these animals obtain access to small islands inhabited by 

 sea-birds or rabbits, the abundant food soon leads to a prodigious increase in their 

 numbers; but sooner or later they practically exterminate the indigenous 

 inhabitants, and then have to seek a more precarious livelihood by preying upon 

 the crustaceans and molluscs on the shores. Some years ago the number of rats 

 in the slaughter-houses around Paris was so great, that as many as 2650 were 

 killed in a single night, and over 16,000 within a month. 



Rats, impelled by scarcity of provisions, at times make migrations in large 

 bodies generally, or always during the night ; and on such journeys they will 

 not hesitate to plunge boldly into and swim over such rivers as may come in their 

 way; and it is related that instances have occurred of their being suddenly 

 hemmed in during such voyages by a rapid formation of ice. Some years ago the 



