Popular Science Monthly/Volume 4/January 1874/An Episode on Rats


THE Norway rat, of which we wish to say a few words, is the Lemming, a species of the mouse-tribe, somewhat smaller than the Guinea-pig, to which in form it bears a considerable resemblance, only the head and body are flatter. Its length is about six inches, of which the short stump of a tail forms half an inch. It is black in color, mottled with tawny spots, which vary in their disposition in different individuals, and the belly is white, with a slight tinge of yellow. The fore-legs are short and strong, and the hind-legs are nearly one-half longer than the former, enabling it to run with considerable speed. The feet are armed with strong hooked claws, five in number, enabling it to burrow in the earth, and among the frozen snows of its native region. Its cheeks are blanched, and it sports a pair of long light whiskers, and its eyes, though small, are beautifully black and piercing. The lip is divided, and the ears are small and sharply pointed. As its home borders on the region of eternal snow, in the valleys of the Kolen Mountains, which separate Sweden from Nordland, its hair is both thick and soft, and becomes almost white during the long and cheerless winter of these inhospitable regions. The skin is much thinner than in any of its congeners. When enraged it gives utterance to a sharp yelp, similar to that of a month-old terrier-whelp.

It is a lively little fellow, when met with in its native haunts, during the short summer—now sitting on its haunches nibbling at a piece of lichen, or the catkins of the birch, which it conveys to its mouth with its fore-paws, after the manner of the squirrel, or engaging in a romp with its fellows, popping in and out of its burrow in the earth where it sleeps and rears its young, of which the female has two or three litters annually, numbering from five to seven in each. It is a most audacious little fellow, and fears neither man nor beast, refusing to give way save on the compulsion of superior force. Travelers speak of having seen them frisking about in hundreds in their native forests, when they dispute the path even with man. From the vantage-ground of the mounds of earth at the entrance to their burrows, they sit on their beam-ends and scan the intruders with comical gravity. If the traveler has a dog with him, unhappily ignorant of the ways of this cool and impudent varmint, he will likely advance with the easy non-chalance of his tribe to smell the odd little animal—which betrays no fear at his approach—to be rewarded by a sharp and trenchant bite on the nose; a reception so sudden and unexpected that it is ten chances to one against his prosecuting his investigations further, for a dog is too well bred to attack any strange living object which awaits his approach.

PSM V04 D359 Lemming or norway rat.jpg

Lemming, or Norway Rat.

Unlike many of its congeners, the lemming does not provide a sufficient store of food to last it through the long winter, when the earth is covered with snow, and, as it does not hibernate, it is driven to many a hard shift in its struggle for a subsistence. It devours the bark of trees and small twigs, and drives tunnels through the snow, along the surface of the ground, eating every shred of vegetation it meets with. These food-burrows are all connected with a main burrow, leading to its home in the earth, which is ventilated by a hole driven obliquely through the snow to the surface. These air-shafts guide the arctic fox and the ermine to their whereabouts, and they devour many of them, while kites and other predaceous birds are ever on the watch to pick them up when they emerge upon the surface. The natives of these regions kill and eat them during summer, when they are in good condition; and a traveled friend of ours, who has partaken of its flesh, speaks of it as a most valuable addition to their scanty cuisine. When captured young, it is easily tamed and becomes an interesting pet. We saw one once in the possession of a Montrose skipper, which allowed itself to be handled and fed out of the hand, but it had an awkward habit of fixing its incisors into the fingers of an incautious admirer on the smallest provocation. During summer they swarm with vermin to such an extent that, although when examined singly they can scarcely be discerned by the naked eye, they change the color of the animal to a dull red.

The lemming multiplies so rapidly that in the course of ten or twelve seasons food becomes scarce, and, on the approach of some winter when the food-question has become one of life or death, the overstocked market is relieved by an expedient unparalleled in its nature among four-footed animals. This singular little creature is so local in its habits, that, unless under the circumstances we are about to narrate, it never leaves the mountain-regions to establish itself on the plains, where food is more abundant.

The inhuman suggestion of a modern writer that our paupers should be packed into rotten ships, which should be sent out to sea and scuttled, is something like the method adopted by the lemmings themselves to avert the famine which threatens to annihilate the entire species. When the time for the settlement of the question of partial extermination for the benefit of the race, or total extermination by starvation, can no longer be delayed, they assemble in countless thousands in some of the mountain valleys leading into the plains, and, the vast army of martyrs being selected, they pour across the country in a straight line, a living stream, often exceeding a mile in length, and many yards in breadth, devouring every green thing in their line of march; the country over which they have passed looking as if it had been ploughed, or burned with fire. They march principally by night, and in the morning, resting during the day, but never seek to settle in any particular locality, however abundant food may be in it, for their final destination is the distant sea, and nothing animate or inanimate, if it can be surmounted, retards the straight onward tide of their advance.

When the reindeer gets enveloped in the living stream, they will not even go round its limbs, but bite its legs until, in its agony and terror, it plunges madly about, crushing them to death in hundreds, and even killing them with its teeth. If a man attempts to stem the living torrent, they leap upon his legs; and, if he lay about him with a stick, they seize it with their teeth, and hold on to it with such determined pertinacity that he may swing it rapidly round his head without compelling them to loosen their hold. If a corn or hay rick be in the way, they eat their way through it; and, on arriving at the smooth face of a rock, they pass round it, forming up in close column again on the other side. Lakes, however broad, are boldly entered, and the passage attempted; and rivers, however deep and rapid, are forded, impediments in the water being as boldly faced as those on shore. They have been known to pass over a boat, and to climb on to the deck of a ship, passing, without stop or stay, into the water on the further side.

Their natural instincts are not in abeyance during this migration, as females are frequently seen accompanied by their young, and carrying in their teeth some one which had succumbed to the fatigues of the march, which might not be stayed until the helpless one was recruited.

Foxes, lynxes, weasels, kites, owls, etc., hover on their line of march and destroy them in hundreds. The fish in the rivers and lakes lay a heavy toll upon them, and vast numbers are drowned, and die by other accidents in "flood and field;" but the survivors, impelled by some irresistible instinct, press onward with no thought of stopping, until they lose themselves in the sea, sinking in its depths, as they become exhausted, in such numbers that for miles their bodies, thrown up by the tide, lie putrefying on the shore. Comparatively few ever return to their native haunts, but there can be no doubt that some do so, as they have been seen on the return, pursuing their backward journey in the same fearless and determined manner as their advance.

The peasants witness this dread incursion with terror. Until lately they believed that the vast horde was rained from heaven as a punishment for their sins, and during the time of their passage they used to assemble in the churches, the priests reciting prayers specially composed for such visitations. It was also believed that the reindeer ate them, and that they so poisoned the ground they passed over that they would not eat on it for a considerable time. As we have seen, the reindeer bites them with its teeth in its agony and terror, and the complete sweep they make of every blade of grass on their line of march satisfactorily accounts for its declining for a time to graze upon it.

A recent writer tells us that, in addition to this wholesale migration, which takes place about twice during a quarter of a century, smaller migrations occur, in which many are killed, while others live to return to their haunts; but as there are several species of lemmings spread over the northern regions of both the Old and the New World, he may allude to another variety than the one we have been dealing with, which is the Mus lemmus of Linnæus and Pallas.

The superstitious notions and wonderful reports once prevalent with regard to the lemming, as recorded by old writers, are not without interest. Olaus Magnus says:

"In the foresaid Helsingia, and provinces that are near to it, in the diocese of Upsal, small beasts with four feet, that they call Lemmar or Lemmus, as big as a rat, with a skin diverse-colored, fall out of the ayr in tempests and sudden storms; but no man knows from whence they come—whether from the

remoter islands, and are brought hither by the wind, or else they breed of feculent matter in the clouds; yet this is proved, that so soon as they fall down there is found green grass in their bellies not yet digested. These, like locusts, falling in great swarms, destroy all green things, and all dyes they bite on, by the venome of them. This swarm lives so long as they feed on new grass. Also they come together in troops like swallows that are ready to fly away; but at the set time they either dye in heaps with a contagion of the earth (by the corruption of them the ayr grows pestilentiall and the people are troubled with vertigos or the jaundice); or they are devoured by beasts called commonly lekeirt or hermalins, and these Ermines grow fat thereby, and their skins grow larger."

Schœffer, whom we next cite, believed that

"They sometimes make war, and divide themselves into two armies along the lakes and meadows. They seem likewise to commit suicide, for they are found suspended in the branches of trees; and they probably throw themselves in troops into waters, like the swallows."

Although prepared to believe that they hanged themselves, he did not believe that they were bred in the clouds. He says:

"Wormius thinks plainly that they are bred in the clouds; but the learned Isaac Rossius, in his notes to Pomponius Mela, corrects him and says, the reason why these animals are supposed to fall from the clouds is, because they used not to appear, but immediately after rain they creep out of their holes, either for that they are filled with water, or because this creature thrives much in rain, which opinion seems most probable to me."

Pontoppidan, writing at a later period, says:

"They multiply very fast by what we see of them, though, God be praised, but seldom, i. e., about once or twice in twenty years, when they come from their peculiar abodes. At these times they gather in great flocks together, consisting of many thousands, like the hosts of God, to execute his will i. e., to punish the neighboring inhabitants by destroying the seed, corn, and grass; for when this flock advances they make a visible pathway on the earth or ground, cutting off all that is green, and this they have power and strength to do till they reach their appointed bounds, which is the sea, in which they swim a little about, and then sink and drown."

Pontoppidan, who had never seen the lemming alive, although he collected a large amount of interesting information, credible and incredible, regarding it, notes a holiday held in his time throughout Bergen, termed a mouse-festival, which had so far degenerated from its ancient purpose, that the peasants put on their holiday clothes and went to sleep. In former times the day was kept as a solemn fast, "to avert the plague of lemen and other mice, which some pretend have been used to fall down formerly from the clouds."

"Wormius, in his treatise on the lemming, gives an exorcism used on such occasions, of which the following is a translation:

"I exorcise you, pestiferous worms, mice, birds, locusts, or other animals by God the Father Almighty, and Jesus Christ his Son, and the Holy Ghost

proceeding from both, that you depart immediately from these fields, or vineyards, or waters, and dwell in them no longer, but go away to those places in which you can harm no person; and on the part of the Almighty God, and the whole heavenly choir, and the holy Church of God, cursing you whithersoever ye shall go, daily wasting away and decreasing until no remains of you are found in any place, unless necessary to the health and use of man, which may He vouchsafe to do who shall come to judge the living and the dead and the world by fire. Amen."

Traveling rapidly and by night, their sudden irruption into a locality, together with the complete destruction of the field and garden crops, tended to make the ignorant peasantry look upon them as a special visitation from Providence for their sins, and will readily account for the extraordinary notions held regarding them.

Many animals migrate from place to place, or take possession of new territory, when food becomes scarce; but we have only one other instance of a living creature migrating in vast numbers to certain destruction, and that is the locust. When their numbers increase beyond the food-producing powers of their natural habitat, they pour in countless millions into the colder regions beyond, smothering each other in their flight, until the ground is covered with their dead bodies to the depth of several inches, and water-courses are choked up by them, until the air is tainted with the smell of their putrid bodies for miles. None of them ever return whence they came. Their course is always onward, until those that escape death by accident are killed by the first cold weather they encounter. And in this way Nature compels, from time to time, a vast body of these creatures to an act of self-destruction in order that the species may not be annihilated.—Abridged from Temple Bar.