Men began by appropriating different names to objects which appeared to them distinctly different, and at the same time, they gave general denominations to such as seemed to resemble each other. Among unenlightened nations, and in the infancy of languages, there are hardly any but general names, or vague or ill-formed expressions for objects of the same order, though in themselves highly different. Thus the oak, beech, linden, fir, yew, pine, had at first no name but that of tree; afterwards the oak, beech, and linden, were called oak, when they came to be distinguished from the fir, pine, and yew, which in like manner would be called fir. Particular names could proceed only from a minute examination of each species, and of course those names would be increased in proportion as the works of Nature were more studied and better understood; the more they studied her, the more generic and specific names would be introduced. To represent Nature, therefore, by general denominations, or genera, is to refer us back to the dark and infant state of human knowledge. Ignorance produced genera, but science will ever continue to create proper names; and we shall not be afraid of increasing the number whenever we have occasion to delineate different species.
Under the generic name of rat several species of little animals have been comprised and confounded; but we appropriate this name solely to the common rat, which is of a blackish colour, and lives in our houses; they generally inhabit barns and granaries, from whence, when food is scarce they invade our dwellings. The rat is carnivorous, or if the expression may be allowed, an omnivorous animal; he prefers hard substances to soft ones, he gnaws wool, linen, and furniture of all sorts; eats through wood, makes holes and hiding places in walls, ceilings, and behind wainscots, from whence he issues in search of food, and frequently returns with as much as he can drag along, forming, especially when he has young to provide for, a magazine of the whole. The females bring forth several times in the year, though mostly in the summer, and have five or six at a time. They love warmth, and in winter they generally shelter themselves near chimneys, or among hay and straw. In defiance of cats, poison, and traps, these animals multiply so much as frequently to do considerable damage. In old country-houses, where great quantities of grain are kept, and where neighbouring barns and hay-stacks favour their retreat and their increase, they often become so numerous that the inhabitants are under the necessity of quitting their dwellings, unless they happen to devour each other, and this is no uncommon thing when they are straightened for provisions; for in case of a famine being occasioned by their numbers the strong kill the weak, open their heads, first eat the brains, and then the rest of the body: the next day hostilities are renewed in the same manner, nor do they suspend their havock until the majority are destroyed; and this is the reason why, in a place that has been for some time infested with rats, they seem to disappear of a sudden, and return not for a long time. It is the same with field-mice, whose prodigious increase is checked solely by their cruelties to each other when provisions become scarce. Aristotle attributes their sudden destruction to the effect of rains, but rats are not exposed to the weather, and field-mice know well how to secure themselves from its effects, for their subterraneous habitations are not even moist.
Rats are as lascivious as voracious; they have a kind of yelp in their amours, and when they fight they cry. They prepare a bed for their young, and almost immediately provide them with food; and when they first quit their hole the mother watches, defends, and will even fight the cats to save them. A large rat is more mischievous, and almost as strong as a young cat; its fore-teeth are long and strong; and as the cat does not bite hard, but is obliged to depend upon her claws, she must not only be vigorous but well experienced in warfare. The weasel, though smaller, is yet a more dangerous enemy, because he can follow the rat into its hiding places: the combat between these two is often sharp and long, from their strength being nearly equal, but their manner of fighting is different. The rat can only wound by snatches, and with his fore-teeth, which are more calculated for gnawing than biting, and have but little strength; whereas the weasel bites fiercely with his whole jaw, and instead of letting go sucks the blood thro' the wound, and therefore the rat always falls a victim to this formidable enemy.
There are many varieties in this species, as in all those which have numerous individuals. Besides the common rat which is nearly black, there are some brown, grey, reddish, and quite white. The white rat, like all animals perfectly white has red eyes. The whole species, with all its varieties, appear to be natives of temperate climates, and have been diffused in much greater abundance over warm countries than cold ones. Originally they had none in America, but were transported with the first European settlers, and where they increased so fast as to become the pest of the colonies, and where indeed they had no enemies but the large serpents which swallowed them up alive. The European ships have also carried them into the East Indies, all the islands of the Indian Archipelago, and into Africa, where they are now found in great numbers. In the north they have never multiplied beyond Sweden, and those which are called Norway and Lapland rats, are animals of a different species.
SUPPLEMENT.
It is asserted by Pontoppidan, that rats cannot live further north than Norway, and that those on the banks of the south side of the river Vorman, very soon die if they are taken to the north, which he attributes to the exhalations of the soil. From the Vicomte Querhoënt I understand that rats multiplied so fast on their first introduction to the isle of France, as even to compel the Dutch to leave it: they have been somewhat lessened by the French, but they still remain in great numbers. He adds, that when a rat has resided some time in India he acquires a very strong smell of musk; and this is confirmed by M. la Boullaye-le-Goux in his voyages. The Dutch voyagers also say that there are scented rats in Madura.
THE MOUSE.
The mouse is much smaller than the rat, more numerous and more generally diffused. Its instinct, temperament, and disposition is the same; and it differs only in its weakness, and the habits resulting from it. Timid by nature, and familiar from necessity, fear and want are the sole springs of its actions. It never leaves its hiding place but to seek for food; nor does it go from house to house, like the rat, unless forced; nor is it near so mischievous; its manners are milder, and to a certain degree it may be tamed, but it is incapable of attachment; how indeed is it possible to love those who are perpetually laying snares for us! Though weak he has more enemies than the rat, from whom he has no means of escape but his agility and minuteness. The owls, birds of prey, cats, weasels, and even rats, make war upon mice, while man, by snares and other means, destroy them by thousands. But for their immense fecundity they could not subsist; they bring forth at all seasons, several times in the year, generally have five or six at a time, and which in less than 15 days are sufficiently strong to shift for themselves. As they so soon attain perfection, their duration of life must be short, a circumstance which must necessarily heighten our ideas of their prodigious multiplication. Aristotle[O] tells us that he put a pregnant mouse into a vessel with plenty of corn, and that he soon after found 120 mice all sprung from the same mother.
[O] Vide Aristotle Hist. Animal. Lib. vi. Cap. 37.
These little animals are not ugly, but have much vivacity and acuteness in their looks; nor is there any foundation for that horror some people hold towards them, but the little surprises and inconveniences they sometimes occasion. All mice are rather white under the belly, some are quite white, others more or less brown or black. The species is generally spread over Europe, Asia, and Africa; but it is said they had no mice formerly in America, and that, though now so very numerous, they were originally brought from the old continent. Certain it is that this little animal, while it fears human society, closely attends it, and this probably from its natural appetite for bread, cheese, bacon, oil, butter, and other kinds of food which man prepares for himself.