The Brown Rat breeds several times during the year, and produces as many as ten, twelve, or fourteen young ones in a litter. Its general length is about nine inches. It may be distinguished from the old English Rat, which it has displaced in most localities, by its greyish-brown colour and by the comparative shortness of its ears, which, when pressed down, do not reach the eye.
The BLACK RAT (Mus rattus), or old English Rat, as it is sometimes called, agrees closely in its habits with the Brown Rat. It is smaller than the Brown Rat, measuring only about seven inches in length, but has a comparatively much longer tail and larger ears, which, when pressed forward, cover the eyes. Its colour above is greyish or brownish-black, and the lower parts are dark ash colour. Although the Black Rat has generally been compelled to give way before its larger and more vigorous competitor, it is still widely dispersed, but not in such numbers as formerly, in Europe. Its native country was probably Southern Asia. Nearly allied to it, if indeed specifically distinct, is the EGYPTIAN RAT (Mus alexandrinus). Both these Rats are said to keep more to the upper parts of houses than the Brown Rat.
Although the true Mice are very nearly allied to the Rats, of which they are copies on a small scale (and some of them, at any rate, are as destructive in their way as their larger relatives), they do not excite by any means the same sentiments of disgust with which Rats are generally regarded; ladies, indeed, will sometimes scream at the mere sight of a Mouse, but most of them will admit that, apart from its predatory habits, it is an elegant little creature. The COMMON MOUSE (Mus musculus) seems to be as completely associated with man as the Rat, and has accompanied him in his wanderings to all parts of the world. It is, however, said not to occur in the Sunda Islands. Of its general appearance and habits we need say nothing; they are too familiar to need description. But besides haunting our houses, the Mouse takes up its abode in the rick-yard, and here its devastations are often very serious. The Mice live in the ricks, through which they make passages in every direction, and their fecundity is so great that several bushels of Mice are often destroyed during the removal of a single rick. The Mouse breeds all the year round, and usually produces five or six young at a birth, so that its rapid increase under favourable circumstances is easily understood. Several varieties of the species are well known, especially the Albino form, or White Mouse, which is such a favourite pet with boys. The Common Mouse in England is sometimes patched with white, and we sometimes see in the shops Pied Mice, which are said to be of Indian origin. A pale buff variety is also sometimes met with; and during the removal of a rick some years ago, it was found to be infested by a breed of Mice with a naked wrinkled skin, to which the name of Rhinoceros Mice was given at the time.
Besides these more or less domestic species, there are in Britain two other representatives of the genus Mus, which do not generally frequent houses. One of these is the LONG-TAILED FIELD MOUSE (Mus sylvaticus), sometimes called the Wood Mouse, an exceedingly pretty little creature, rather larger than the Common Mouse, and having a proportionally longer tail. It measures about four inches in length, and the tail is about as long as the body; its colour is yellowish or yellowish-brown on the upper surface, whitish beneath; and the tail is brown above and white beneath. This species is found all over the temperate parts of Europe and Asia, living in the fields and gardens, where it takes up its abode, either in some small cavity under the root of a tree, in the deserted runs of the Mole, or less commonly in a little burrow excavated by its own labour. It feeds chiefly upon grain and seeds, of which it lays up a considerable store for winter use in its subterranean dwelling, and in this way does considerable damage to the crops. The Field Mouse does not, however, strictly confine itself to a vegetable diet, but under circumstances of privation will attack and devour smaller and weaker animals, not even sparing its own species. It breeds more than once in the year, and produces from seven to ten young in each litter. It is easily tamed, and soon becomes familiar.
HARVEST MICE.
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LARGER IMAGE
The remaining British species, the HARVEST MOUSE (Mus minutus), is the smallest of the British quadrupeds, with the exception of the Lesser Shrew (Sorex pygmæus). The Harvest Mouse is to be found in most parts of England. It also occurs in Scotland as far north as Aberdeenshire; and in Ireland, but very rarely. On the Continent its range extends over nearly the whole of Europe, from Russia in the north to Italy in the south. It is well known in Siberia, and occurs abundantly in the steppes near the Caucasus.
The total length of this pretty little Mouse is about five inches, of which nearly one-half is made up of the tail. In it the eyes are less prominent than in the common Field Mouse, and the ears considerably shorter in proportion. Its colour on the upper surface is bright reddish-brown, and below pure white, the two colours being sharply separated. During the summer, the Harvest Mouse associates with the other Field Mice in corn-fields, and with them is very frequently carried in the sheaves of corn to rick-yards and barns, where it then takes up its abode for the autumn and winter, and, like other Mice, multiplies very rapidly, and no doubt does a good deal of mischief. The less fortunate individuals who are left behind in the fields retreat to little burrows for protection from the inclemency of the winter, which they pass in a state of at least partial torpidity; and to provide against exigencies they lay up in their dwellings a small store of food, to which they can have recourse when a fine day recalls them for a time to activity. Those which have been introduced into ricks and barns are, of course, liberally provided for, and they show their gratitude by remaining awake all the winter, as if on purpose to consume their abundant provender. In the open field their food consists of corn and the seeds of grasses and other plants, but also to a considerable extent of small insects.
In its movements the Harvest Mouse is wonderfully agile. On the ground it runs very rapidly; and it climbs upon shrubs and plants as cleverly as a Monkey, running out upon the thinnest twigs with the greatest confidence, and climbing up stalks of grasses so thin that they bend nearly to the ground with its weight. In these operations the long slender tail comes into use, as its extremity is prehensile, and can be twisted neatly round the small stalks and branches over which the little climber is making its way. From its lively habits, and the elegance of its form, the Harvest Mouse is a very interesting pet.