“The rat, though small, weak, and contemptible in its appearance,
possesses properties that render it a more formidable enemy to mankind,
and more injurious to the interests of society, than even those animals
that are endued with the greatest strength and the most rapacious
dispositions. To the one we can oppose united powers and superior arts;
with regard to the other, experience has convinced us that no art can
counteract the effects of its amazing fecundity, and that force is
ineffectually directed against an animal possessed of such variety of
means to elude it.
“There are two kinds of rats known in this country,--the black rat,
which was formerly universal here, but is now very rarely seen, having
been almost extirpated by the large brown kind, which is generally
distinguished by the name of the _Norway rat_.
“This formidable invader is now universally diffused through the whole
country, from whence every method has been tried in vain to exterminate
it. This species is about nine inches long, of a light-brown colour,
mixed with tawny and ash; the throat and belly are of a dirty white,
inclining to grey; its feet are naked, and of a pale flesh-colour;
the tail is as long as the body, covered with minute dusky scales,
thinly interspersed with short hairs. In summer it frequents the banks
of rivers, ponds, and ditches, where it lives on frogs, fishes, and
small animals. But its rapacity is not entirely confined to these. It
destroys rabbits, poultry, young pigeons, &c. It infests the granary,
the barn, and the storehouse; does infinite mischief among corn and
fruit of all kinds; and not content with satisfying its hunger,
frequently carries off large quantities to its hiding-place. It is a
bold and fierce little animal, and when closely pursued, will turn and
fasten on its assailant. Its bite is keen, and the wound it inflicts is
painful and difficult to heal, owing to the form of its teeth, which
are long, sharp, and of an irregular shape.
“The rat is amazingly prolific, usually producing from twelve to
eighteen young ones at one time. Their numbers would soon increase
beyond all power of restraint, were it not for an insatiable appetite,
that impels them to destroy and devour each other. The weaker always
fall a prey to the stronger; and a large male rat, which usually
lives by itself, is dreaded by those of its own species as their most
formidable enemy.
“It is a singular fact in the history of those animals, that the skins
of such of them as have been devoured in their holes have frequently
been found curiously turned inside out, every part being completely
inverted, even to the ends of the toes. How the operation is performed
it would be difficult to ascertain; but it appears to be effected in
some peculiar mode of eating out the contents.
“Besides the numbers that perish in these unnatural conflicts, they
have many fierce and inveterate enemies, that take every occasion to
destroy them. Mankind have contrived various methods of exterminating
these bold intruders. For this purpose traps are often found
ineffectual, such being the sagacity of the animals, that when any
are drawn into the snare, the others by such means learn to avoid the
dangerous allurement, notwithstanding the utmost caution may have
been used to conceal the design. The surest method of killing them
is by poison. Nux vomica ground and mixed with oatmeal, with a small
proportion of oil of rhodium and musk, have been found from experience
to be very effectual.
“The water-rat is somewhat smaller than the Norway rat; its head larger
and its nose thicker; its eyes are small; its ears short; scarcely
appearing through the hair; its teeth are large, strong, and yellow;
the hair on its body thicker and longer than that of the common rat,
and chiefly of a dark brown colour mixed with red; the belly is grey;
the tail five inches long, covered with short black hairs, and the tip
with white.
“The water-rat generally frequents the sides of rivers, ponds, and
ditches, where it burrows and forms its nest. It feeds on frogs, small
fish and spawn, swims and dives remarkably fast, and can continue a
long time under water.”[1]
[1] Bewick’s _History of Quadrupeds_, 1790, 354 _et seq._
In Mr. Charles Fothergill’s _Essay on the Philosophy, Study, and Use of
Natural History_ (1813), we find some reflections which remind us of
Ray and Derham. We shall extract a few paragraphs which relate to the
subject in hand.
“Nothing can afford a finer illustration of the beautiful order and
simplicity of the laws which govern the creation, than the certainty,
precision, and regularity with which the natural checks in the
superabundant increase of each tribe of animals are managed; and
every family is subject to the operation of checks peculiar to the
species--whatever it may be--and established by a wise law of the
Most High, to counteract the fatal effects that might arise from an
ever-active populative principle. It is by the admirable disposition
of these checks, the contemplation of which is alone sufficient to
astonish the loftiest and most comprehensive soul of man, that the
whole system of animal life, in all its various forms, is kept in due
strength and equilibrium.
“This subject is worthy of the naturalist’s most serious consideration.”
“This great law,” Mr. F. proceeds, “pervades and affects the whole
animal creation, and so active, unwearied, and rapid is the principle
of increase over the means of subsistence amongst the inferior animals,
that it is evident whole genera of carnivorous beings amongst beasts,
birds, fish, reptiles, and insects, have been created for the _express
purpose_ (?) of suppressing the redundancy of others, and restraining
their numbers within proper limits.
“But even the natural checks are insufficient to restrain the effects
of a too-rapid populative principle in some animals, which have,
therefore, certain destructive propensities given to them by the
Creator, that operate powerfully upon themselves and their offspring,
as may be particularly observed in the natural history of the _rabbit_,
but which is still more evidently and strikingly displayed in the life
and economy of the _rat_.
“It has been calculated by Mr. Pennant, and there can be no doubt of
the truth of the statement, that the astonishing number of 1,274,840
may be produced from a single pair of rabbits in the short space of
four years, as these animals in their wild state breed seven times in
a-year, and generally produce eight young ones each time. They are
capable of procreation at the age of five or six months, and the doe
carries her burthen no more than thirty days.
“But the principle of increase is much more powerful, active, and
effective in the common grey rat than in any other animal of equal
size. This destructive animal is continually under the _furor_ of
animal love. The female carries her young for one month only; and she
seldom or never produces a less number than twelve, but sometimes as
many as eighteen at a litter--the medium number may be taken for an
average--and the period of gestation, though of such short continuance,
is confined to no particular season of the year.
“The embraces of the male are admitted immediately after the birth
of the vindictive progeny; and it is a fact which I have ascertained
beyond any doubt, that the female suckles her young ones almost to the
very moment when another litter is dropping into the world as their
successors.
“A celebrated Yorkshire rat-catcher whom I have occasionally employed,
one day killed a large female rat, that was in the act of suckling
twelve young ones, which had attained a very considerable growth;
nevertheless, upon opening her swollen body, he found thirteen
quick young, that were within a few days of their birth. Supposing,
therefore, that the rat produces ten litters in the course of a year,
and that no check on their increase should operate destructively for
the space of four years, a number not far short of 3,000,000 might be
produced from a single pair in that time!
“Now, the consequence of such an active and productive principle of
increase, if suffered continually to operate without check, would soon
be fatally obvious. We have heard of fertile plains devastated, and
large towns undermined, in Spain, by rabbits; and even that a military
force from Rome was once requested of the great Augustus to suppress
the astonishing numbers of the same animal overrunning the island of
Majorca and Minorca. This circumstance is recorded by Pliny.
“If, therefore, rats were suffered to multiply without the restraint
of the most powerful and positive natural checks, not only would
fertile plains and rich cities be undermined and destroyed, but the
whole surface of the earth in a very few years would be rendered
a barren and hideous waste, covered with myriads of famished grey
rats, against which man himself would contend in vain. But the same
Almighty Being who perceived a necessity for their existence, has also
restricted their numbers within proper bounds, by creating to them many
very powerful enemies, and still more effectually by establishing a
propensity in themselves, the gratification of which has continually
the effect of lessening their numbers, even more than any of their
foreign enemies.
“The male rat has an insatiable thirst for the blood of his own
offspring; the female, being aware of this passion, hides her young
in such secret places as she supposes likely to escape notice or
discovery, till her progeny are old enough to venture forth and stand
upon their own energies; but, notwithstanding this precaution, the
male rat frequently discovers them, and destroys as many as he can;
nor is the defence of the mother any very effectual protection, since
she herself sometimes falls a victim to her temerity and her maternal
tenderness.
“Besides this propensity to the destruction of their own offspring,
when other food fails them, rats hunt down and prey upon each other
with the most ferocious and desperate avidity, inasmuch as it not
unfrequently happens, in a colony of these destructive animals, that
a single male of more than ordinary powers, after having overcome and
devoured all competitors with the exception of a few females, reigns
the sole bloody and much-dreaded tyrant over a considerable territory,
dwelling by himself in some solitary hole, and never appearing abroad
without spreading terror and dismay even amongst the females whose
embraces he seeks. In this relentless and bloody character may be found
one of the most powerful and positive of the checks which operate to
the repression of this species within proper bounds; a character which
attaches, in a greater or less degree, to the whole _Mus_ genus, and in
which we may readily perceive the cause of the extirpation of the old
black rats of England, _Mus rathus_; for the large grey rats, having
superior bodily powers united to the same carnivorous propensities,
would easily conquer and destroy their black opponents wherever
they could be found, and whenever they met to dispute the title of
possession or of sovereignty.”
When the young rats begin to issue from their holes, the mother
watches, defends, and even fights with the cats, in order to save them.
A large rat is more mischievous than a young cat, and nearly as strong:
the rat uses her fore-teeth, and the cat makes most use of her claws;
so that the latter requires both to be vigorous and accustomed to
fight, in order to destroy her adversary.
The weasel, though smaller, is a much more dangerous and formidable
enemy to the rat, because it can follow it into its retreat. Its
strength being nearly equal to that of the rat, the combat often
continues for a long time, but the method of using their arms by the
opponents is very different. The rat wounds only by repeated strokes
with his fore-teeth, which are better formed for gnawing than biting;
and, being situated at the extremity of the lever or jaw, they have
not much force. But the weasel bites cruelly with the whole jaw, and,
instead of letting go its hold, sucks the blood from the wounded part,
so that the rat is always killed.