RAT. 



527 



tat of all kinds. Hence we have had stories of them 

 making their holes in the bodies of pigs when k ]>t 

 long in a state of great obesity. We believe that 

 there are well-authenticated instances of the toes and 

 part of the feet of bed-rid and neglected persons 

 being eaten away by rats ; but they, at least used to, 

 carry these matters much farther in Germany ; and 

 a curious ancient tale of a Saxon duke is thus 

 transformed from German prose to English rhyme. 



In addition to this fondness for animal matter, there 

 is little doubt that the mice and rats destroy a vast 

 number of offensive animals and offensive substances. 

 It is well known that the mice are great eaters of 

 those beetles which so much infest houses during 

 the night ; and there is no doubt that in cities where 

 there is an under drainage by sewers the brown rats, 

 which make the sewers their principal haunts, con- 

 tribute not a little both to cleanliness and health. As 

 matters are at present, the drainage of London stains 

 the water of the Thames as much as the fondest 

 admirer of substantial waters could wish for ; but 

 when we take into consideration the countless millions 

 of brown rats which are supported in the sewers, and 

 of which the greater part are produced, and live, and 

 feed, and thrive there, without any other store for 

 their support, we can readily understand what would 

 be the case of matters were it not for them. In this 

 view of the matter, the murine races, whether they 

 come under the common name of rats or of mice, are 

 in this respect highly useful, that they play the sca- 

 venger for man in cases where he either cannot or 

 will not play it for himself. -Every animal indeed 

 which follows man in all his migrations, and multi- 

 plies in proportion as his numbers multiply, is always 

 useful to him. Most of these animals are, no doubt, 

 annoying, and many of them are positively offensive; 

 but, in all cases where they are so, man will rind that 

 he himself is generally to blame. They come to 

 consume that which is at variance with health and 

 cleanliness ; and if the latter is properly attended to, 

 there is no place for them. 



In the family under consideration, there appear to 

 be species, chiefly of rats, which are the most power- 

 ful and efficient, suited to different states of society. 

 This is well exemplified in the two species of rat 

 which are found about habitations in Britain, and 

 indeed in most temperate countries the black rat 

 and the brown one. The black rat is the oldest in- 

 habitant of the country, or, at all events, it was plen- 

 tiful in former times, when the brown rat was com- 

 paratively rare ; and its numbers have fallen off very 

 much, while those of the other one have increased in 

 a far greater proportion. 



The usual method of explaining this is to say that 

 the brown rat has eaten up the black one, and done 

 so to absolute extermination in many instances. But 

 both the analogical presumption and the observed 

 facts are against this. If the brown rat had come to 

 eat up the black one, the increase of its number 

 should have become less, and so indeed should its 

 numbers altogether, as those of the other were eaten 

 up. The fact, however, is exactly the reverse of this ; 

 for the brown rat has, in all cases in which observa- 

 tion has been made, increased much faster after the 

 total disappearance of the black rat than it did before. 



Besides, there are some parts of the country where 

 both species haunt the very same buildings, and there 

 is no account of any instance in which the one species 

 made an attack on the other. Rats, as we have 

 hinted, are not very particular in their eating ; and, if 

 pushed to extremities, it is very likely they would eat 

 their own species ; but this is not their general food, 

 for we know of no animals, even in the sea, where 

 cannibalism is by far the most common, far less on 

 the land, which are entirely, or even chierly, self-sup- 

 ported in the way of food. This would, in fact, be 

 defeating the grand purpose of nature, which runs 

 through and is observable in all that lives and in all 

 that grows, namely, that of each being supported 

 upon the surplus of another. 



When they have been found together in the same 

 house or other building, these two species of rats have 

 always taken up separate localities ; and localities 

 which show that they are adapted to different states 

 of society, or, which is the same in effect, to become 

 of different character and construction. The black rat 

 is properly a murine animal, lodging in holes of walls 

 and crevices of roofs, and therefore it lodges higher 

 than the other. The brown rat is more an animal of 

 the foundations, loving cold and damp, and preferring 

 a sewer or drain to a palace. As inhabitants of the ' 

 same building, therefore, the two do not come upon 

 each other's ground in such a way as that the one 

 could exactly replace the other, and this leads us to 

 the particular state of men and their dwellings, In 

 which the one or the other is likely to be the common 

 rat. 



Mud walls, and turf and thatch roofs, are the places 

 for the black rat, because it can most readily find or 

 form a lodging for itself there; and although during 

 the night they may range on the ground, their escape 

 is always to the upper part of the building. There is 

 no better authority than Burns as to the conduct of 

 all rural creatures, and indeed all creatures whatever 

 that came under his observation. In his time, what- 

 ever may be the case now, those parts of Scotland to 

 which his observations were principally directed 

 abounded much in mud walls, and still more in 

 thatched roofs in roofs particularly well adapted for 

 affording lodgings for the black rat, in which it could 

 rear its litter, or hide itself during the day. In " the 

 Vision," where he gives so true a picture of the tem- 

 poral privations to which he was subjected in con- 

 sequence of his devotedness to the muse, he, without 

 specially intending it, throws more light upon the 

 habitation and character of the black rat than all the 

 professed naturalists have written on the subject. 

 He says that, as he sat " right pensilie" by the fire in 

 the " spence," or inner room of the rude old-fashioned 

 farm-house, " musing backwards on misspent time," he 



' Sat an' e'ed the spewing reek, 

 That filled with host- provoking: smeek 



The auld cluii hit;: 

 An" heard the restless rattans squeak 



Atnnin the riggin'." 



Burns did not, like the " starveling bards of these 

 degenerate days," who gather poppy petals for the 

 fine but fading winter nosegays of easy printing, use 

 to hunt for inapplicable epithets to make his rhyme 

 clink. With him, wherever he came by the art, the 

 word which is best in rhyme is always best in reason 

 too ; and on this account he is a first-rate authority 

 in all points of natural history which he touches. 

 The " auld clay biggin' " is ,the very place for the 



