Rat, a well known rodent, the type of the subfamily murinoe. In the murine tribe of this subfamily, confined originally to the old world, belong the common house rats. The brown or Norway rat (mus decumanus, Pall.) has a body 8 to 10 in. long, and the tail 6 to 8 in., scantily covered with hair and with about 200 rings; the color above is grayish brown mixed with rusty, grayer on the sides, and ashy white below; the upper surface of the feet dirty white. This species, originally from India and Persia, entered Europe through Russia, appearing in the central countries about the middle of the 18th century; it was brought to America about 1775, and has since greatly increased in numbers, driving out here as in Europe the black rat which had been previously introduced; it is now generally distributed over the world, having been transported in ships, and most abundantly near the seacoasts. Its haunts are cellars, sewers, canal docks, and similar dirty places, wherever it can make a burrow or find abundant food; it is a great household pest, and so prolific that its devastations are sometimes very great; it breeds from three to five times a year, having 12 to 15 at a birth, the males always being the most numerous.
Not only the black rat, but other species indigenous to the old world, are driven off or destroyed by it; the dead and even living persons are attacked by it when hard pressed; it is not only pursued by man, dogs, and cats, but the stronger will kill and devour the weaker of its own species. The black rat (M. rattus, Linn.) is 7 or 8 in. long, with a tail of 8 1/2 in.; the color is very dark, often nearly black, with numerous long hairs projecting from the short and soft fur, plumbeous beneath, and the feet brown; it has a slighter form than the brown rat, with the upper jaw more projecting, the ears larger, and the tail much longer in proportion. It is not very strong, but exceedingly active; being rather timid, it is exterminated by the larger and fiercer brown rat; the habits of the two species are much the same, but the black rat is less a burrowing animal, and prefers the upper parts of houses to cellars and low dirty places. It used to be the common house rat in Europe and warm countries, until driven off by its congener; it appears to have been brought to the new world about the middle of the 16th century; it came originally from central Asia; like the preceding species, it is omnivorous.
The roof or white-bellied rat (M. tec-torum, Savi) is about 6 1/2 in. long, and the tail about 8 in. with 240 rings; it is colored above like the brown rat, the lower parts and upper surface of feet yellowish white; the head is rather blunt, the eyes large, whiskers long and black, ears very large, and the thumb rudimentary. It came originally from Egypt and Nubia, thence passed to Italy and Spain, and from the last to America in the 15th century; it is common in Mexico and Brazil, and in the southern states, but is rarely found above North Carolina; it is fond of inhabiting the thatched roofs of houses, whence its name; it is the same as the M. Alexandrinus (Geoffr.) and M. Americanus (Seba). Some of the East Indian rats are far larger than any of these; the giant rat of Bengal and the Coromandel coast (M. giganteus, Raffles) has a body 13 in. long and a tail as much more; this is very destructive in gardens and granaries, devouring chickens and ducks, undermining houses, and piercing the mud walls; it is the largest of the subfamily, a male weighing as much as 8 lbs.; it is often eaten by the lower caste Hindoos. - All these rats are very fond of fighting, and with their omnivorous habits are decidedly murine cannibals, eating not only their conquered brethren but their young.
Though living in the filthiest places and in the foulest air, they always have a sleek coat, and take the greatest pains to clean themselves, licking the paws in the manner of a cat; during mastication the jaws move very rapidly; they drink by lapping; when asleep the body is coiled in a ball, with the nose between the hind legs, and the tail curled around the outside, leaving only the ears out ready to catch the least sound of danger; as food fails they migrate in companies from one place to another. There are more muscles in a rat's tail than in the human hand; this most useful appendage, with its chain of movable bones and numerous muscles, is covered with minute scales and short stiff hairs, rendering it prehensile, and capable of being employed as a hand, balancer, or projecting spring. The teeth are long and sharp, but there is nothing specially dangerous in wounds made by them; their strength enables them to gnaw ivory, as dealers in this article well know; in fact, even in Africa, elephants' tusks are found gnawed by rats, squirrels, porcupines, and perhaps other rodents, as long as any gelatine is contained in them. They are very subject to tumors of the skin, which often end fatally; they also perish soon without water.
These animals have their uses, especially for devouring refuse matters which would otherwise engender disease, as in tropical climates or in large cities, in the sewers of which they live in legions; their skins are employed for various purposes, as in the manufacture of the thumbs of gloves, but are too delicate for any article requiring much strength. The Chinese and other Asiatic nations, and many African tribes, eat the flesh of rats; and arctic travellers have often found them a welcome addition to their bill of fare. - In the sigmodont tribe of the murium, belonging entirely to the new world, besides the genera noticed tinder Mouse, may be mentioned neo-toma (Say and Ord); in this the fur is soft and full, the form rat-like, the tail long and more or less hairy; ears very large and nearly naked; molars rooted; heels hairy. It is peculiar to North America, and found in the United States except New England; some of the species are much larger than house rats, and are rather handsome. The Florida or wood rat (N. Floridana, Say and Ord) is about 8 in. and the tail 6 in. long, the short stiff hair of the latter not concealing the scaly rings; the color above is plumbeous mixed with dark and yellowish brown, lighter on the sides, beneath and the feet white; tail dusky above, white below; the head is sharp.
It is abundant in the southern Atlantic and gulf states, and is found occasionally in the west; the habits vary much in different localities, living in some places in the woods, in others under stones or in the ruins of buildings; in swampy districts it heaps up mounds, 2 or 3 ft. high, of grasses, leaves, and sticks cemented with mud; sometimes the nest is in the fork or the hollow of a tree. It is crepuscular, very active and an excellent climber; the food consists of corn, nuts, cacti, crustaceans, mollusks, and various roots and fruits; the disposition is mild and docile; from three to six young are produced twice a year. Larger species are found west of the Rocky mountains, very destructive to the furs, blankets, and stores of the trappers; for an account of these see vol. viii. of the "Reports of the Pacific Railroad Expedition." In the bone caves of Pennsylvania have been found the remains of a species whose body must have been at least 12 in. long. - In the genus sigmodon (Say and Ord) the general appearance is that of a large field mouse; the body is stout, the hair long, the muzzle blunt and hairy except on the septum; the upper lip slightly notched; thumb rudimentary; soles naked, with six granular tubercles; incisors stout, the upper much rounded; ears and tail moderate; molars rooted, with a plane surface, the last two lower with the enamel in the form of an S, whence the name.
The genus is confined to the southern parts of the United States. The best known species is the cotton rat (8. hispi-dus, Say and Ord), about 5 in. long with a tail of 4 in.; the color above is reddish brown, brightest on the sides, lined with dark brown, and under parts grayish white; the hair is long and coarse, and the claws very strong. It is more abundant in the southern states than the meadow mice in the north, living in hedges, ditches, and deserted fields, and consequently doing but little damage to the planter. It is gregarious, feeding on seeds of grasses and leguminous plants, and also on flesh; it picks up wounded birds and small mammals, crawfish, and crabs; it is very fierce and pugnacious, the stronger killing and devouring the weaker, and the males often eating the young; it is also very fond of sucking eggs. Nocturnal in habit, it is seen by day in retired places; it digs very extensive galleries not far from the surface, a family in each hole; it breeds several times a year, having four to eight in a litter; it swims and dives well. It received its name from its lining the nest with cotton. It is preyed upon by foxes, wild cats, hawks, and owls.
It is not found north of Virginia.
Norway Eat (Mus decumanus).
Black Eat (Mus rattus).
Florida Eat (Neotoma Floridana).
Cotton Eat (Sigmodon hispidus).