Chapter Nine. Rats and other Rodents - Book of zoology for boys by Mayne Reid
In this group we include not only Rats, but a great many other small rodents, or gnawers, such as Mice, Marmots, Lemmings, Hamsters, Mole-Rats, Jerboas, and Jumping Mice. The Shrew-Mice and Moles may also be classed here—although naturalists separate them from rodents, because their food is not herbivorous, but consists of worms and insects. For all that, there is a certain general resemblance, both as to appearance and habits, among all these small quadrupeds; which, for purposes of classification, is, perhaps, of more value than mere difference of food, or tubercles upon the teeth; especially, as it can be proved, that the sort of food an animal eats, is often dependent on the circumstances in which it may be placed.
Of the Rats, properly so called, there are numerous species, as well as varieties. Their size is, in general, about the same as the Black and Norway rats—both of which belong to England, and have been introduced, by means of ships, into every country upon the habitable globe. They are said to have come originally from Asia. There is one species of rat, however, that is much larger than either of these—the Gigantic rat, found in Indian countries, and which in size quite equals a rabbit!
The habits of the rats are too well-known to require description. Some—as the Wood Rat and Florida Rat of America—dwell apart from the habitations of man, in the woods; where, instead of living in burrows, they construct large nests, by collecting together heaps of sticks, leaves, and grass.
Mice may be regarded as only a smaller kind of rats; and of these there are many distinct species—both in the Old and New Worlds.
The Marmots are, perhaps, the most interesting of the small rodents. They stand in a sort of connection with the squirrels, more especially the ground squirrels: on the other hand, they resemble rabbits; and they have still many points of identity with rats. They belong to the northern zones of Europe, Asia, and America. There are three or four species belonging to the Old World; and a great many to North America. Moreover there is a considerable difference in the habits of these species, which has led zoologists to separate them into several genera. One genus, called the Seed-eaters, is a very curious kind. The marmots of this genus have a pair of pockets or pouches—one on the outside of each cheek—in which they actually carry seeds and other articles of food to their burrows. These pouches, when filled, impart to the little creatures a most ludicrous appearance.
The marmots usually live in large communities—in burrows, as rabbits do. These burrows are sometimes very extensive—especially so, in the case of the prairie marmot of America—better known as the Prairie Dog—whose villages sometimes cover an extent of many square miles; and whose odd social habits have been repeatedly and accurately described by late travellers who have crossed the American continent.
The Mole-rats are a sort of combination between moles and rats: hence their common name. One species is found in Eastern Russia; where it burrows much after the fashion of the mole—living principally upon roots. Two other kinds belong to South Africa. Both these are of large size, nearly as big as rabbits. On the plains, they make extensive excavations, which often prove dangerous to the horse and his rider—causing the former to stumble. The Dutch of the Cape know them by the name of Sand Moles.
The Hamsters differ considerably from the marmots in their mode of burrowing. They make their underground dwellings very extensive—having a great many chambers and galleries. In these they collect vast stores of food—consisting of grain, peas, and seeds of various kinds. Sometimes two or three bushels of provision will be found in the storehouse of a single family. The hamsters do not confine themselves exclusively to a vegetable diet: since it is known that they will kill and eat birds, or even small quadrupeds. In this respect they resemble the common rats; and, therefore, it is idle to talk of mere herbivorous genera of animals. The hamsters are very fierce little creatures: constantly fighting with other quadrupeds, and even among themselves; but the polecat is their master and tyrant, and carries on a war of extermination against them—following them through the intricate ways of their burrows, and destroying them even in their dens!
There are several species of hamsters in Europe and Asia, and also in North America: for the animal known as the Canada Pouched Rat is of this kind, and so also is the Tucan of Mexico. So also is that very singular and beautiful creature, the Chinchilla of South America—so celebrated for its soft and valuable fur.
The Lemmings are another form of small rodent animals, celebrated for their extraordinary migratory habit; which resembles that of the grey squirrels of North America. There are several species of lemmings belonging to the northern section of the Old Continent—in Eastern Russia and Asia. One or two are found in North America—in that part of it known as the Hudson’s Bay Territory.
The Spinous Rats are little animals much resembling ordinary rats; but with the peculiarity of having stiff spines growing among their hair, after the manner of porcupine quills. There are several species of them: all natives of tropical America.
The Jerboas are, perhaps, the most singular of all the rodents. They are noted for having the hind legs much longer than the fore ones—in fact, being shaped very much like the kangaroos—of which they might be termed Lilliputian varieties, were it not that they lack the pouch, which distinguishes these curious creatures. Like the kangaroos, they use their fore-feet only to rest upon. When in motion, or desirous of passing quickly over the ground, they make use of their hind-feet only: proceeding by long leaps or jumps, and sometimes springing to the distance of twelve or fifteen feet. Their tails being long and slender, were supposed not to assist them in this operation; but an experiment made by a cruel Frenchman—that of cutting off these appendages—proved that a considerable portion of the jumping power is derived from the tail.
Africa and Asia are the head-quarters of these quadrupeds—the most noted species being the Jerboas of Egypt, and the Leaping Hare of the Cape. They dwell in sandy deserts—burrowing in communities like the marmots. In America there are no true jerboas: they are there represented by the Jumping Mice of Labrador and the Hudson’s Bay Territory; which resemble the jerboas in almost everything except size, the jumping mice being much smaller animals.
Field Mice and Dormice are other kinds of small rodents, differing from the common kind of mouse; but the habits and appearance of these little quadrupeds are well-known.
The Beaver and Musk-rat, or Musquash of America, are usually classed among the rat tribe; but these animals, for many reasons, deserve to stand apart and form a group of themselves. With regard to the shrew-mice and moles, there is less reason for separating them from other mice; and we shall speak of them in this connection.
The Moles are known to be the best burrowers in the world: since they can pass under the surface of the ground as fast as a man can dig after them, or even faster. In England, the common mole is well-known—too well, in fact—for it is the very pest of the farmer; and the damage done by it to the herbage is very considerable indeed—of greater amount than that occasioned by any other wild animal.
In America, where there are several species of moles, their habits are similar; and the common American mole is very like its European congener in every respect. But there are two or three species found in North American countries very different from either; and the most singular of all is that known as the Star-nosed Mole. This creature has the cartilage of the snout extended into five or six branches, that radiate from each other, like spokes of a wheel, or the points of a star—hence the name of star-nosed mole. The use of this singular appendage is not clearly understood; and, indeed, it would appear to be an obstruction to the natural requirements of the animal. No doubt, however, it has its purpose—though that purpose be unknown to us.
The Shrew-Mice are still another kind of small ratlike quadrupeds. They are distinguished by having upon each flank, under the ordinary skin, a little band of stiff and close hairs, from which an odoriferous humour is distilled. They dig holes in the earth, which they seldom come out of until towards evening; and their food consists of insects and worms. A species that inhabits the Pyrenees, and also the mountains of Russia, are called Desmans, and differ somewhat from the ordinary shrew-mice. They are aquatic in their habits; and their burrows always enter the ground below the level of the water. The Russian species are usually termed Musk-rats; but these are not to be confounded with the musk-rats of America—which last should undoubtedly be classed with the beavers.
In India, the shrew-mice attain to the size of ordinary rats, and are there also called musk-rats, from the fact that a strong odour of musk is exhaled by them—so strong as to make the place through which the animal passes exceedingly disagreeable. The same is true of the Russian musk-rats, but for all that their skins are employed in chests containing clothing: since the musky smell is a good preservative against the moths.
In addition to the numerous rat animals above-mentioned, there are still other kinds in different parts of the world—the names of which would alone fill many pages. Hence it is that the study of this section of the mammalia is, perhaps, the most difficult of all; and a true classification of these small quadrupeds has hitherto proved a puzzle to the most expert zoologists.