inhabitants suffer oppression, or are not comfortable in it,
emigrations frequently take place, and colonies issue forth to settle
in other parts of the globe; and sometimes whole nations leave
their own country, either driven to this step by their enemies, or
excited by cupidity to take possession of what appears to them a
more desirable residence. These motives operate strongly on some
insects of the social tribes.--Bees and ants are particularly
influenced by them. The former, confined in a narrow hive, when their
society becomes too numerous to be contained conveniently in it,
must necessarily send forth the redundant part of their population
to seek for new quarters; and the latter--though they usually can
enlarge their dwelling to any dimensions which their numbers may
require, and therefore do not send forth colonies, unless we may
distinguish by that name the departure of the males and females from
the nest--are often disgusted with their present habitation, and seek
to establish themselves in a new one:--either the near neighbourhood
of enemies of their own species; annoyance from frequent attacks of
man or other animals; their exposure to cold or wet from the removal
of some species of shelter; or the discovery of a station better
circumstanced or more abundant in aphides;--all these may operate as
inducements to them to change their residence. That this is the case
might be inferred from the circumstance noticed by Gould[91], which
I have also partly witnessed myself, that they sometimes transport
their young brood to a considerable distance from their home. But M.
Huber, by his interesting observations, has placed this fact beyond
all controversy; and his history of their emigrations is enlivened by
some traits so singular, that I am impatient to relate them to you.
They concern chiefly the great hill-ant (_F. rufa_), though several
other species occasionally emigrate.
Some of the neuters having found a spot which they judge convenient
for a new habitation, apparently without consulting the rest of the
society, determine upon an emigration, and thus they compass their
intention: The first step is to raise recruits:--with this view they
eagerly accost several fellow citizens of their own order, caress
them with their antennæ, lead them by their mandibles, and evidently
appear to propose the journey to them. If they seem disposed to
accompany them, the recruiting officer, for so he may be called,
prepares to carry off his recruit, who, suspending himself upon his
mandibles, hangs coiled up spirally under his neck;--all this passes
in an amicable manner after mutual salutations. Sometimes, however,
the recruiter takes the other by surprise, and drags him from the
ant-hill without giving him time to consider or resist. When arrived
at the proposed habitation, the suspended ant uncoils itself, and,
quitting its conductor, becomes a recruiter in its turn. The pair
return to the old nest, and each carries off a fresh recruit, which
being arrived at the spot joins in the undertaking:--thus the number
of recruiters keeps progressively increasing, till the path between
the new and the old city is full of goers and comers, each of the
former laden with a recruit. What a singular and amusing scene is
then exhibited of the little people thus employed! When an emigration
of a rufescent colony is going forward, the negroes are seen carrying
their masters: and the contrast of the red with the black renders
it peculiarly striking. The little turf-ants (_Myrmica? cæspitum_)
upon these occasions carry their recruits uncoiled, with their head
downwards and their body in the air.
This extraordinary scene continues several days; but when all the
neuters are acquainted with the road to the new city, the recruiting
ceases. As soon as a sufficient number of apartments to contain
them are prepared, the young brood, with the males and females,
are conveyed thither, and the whole business is concluded. When
the spot thus selected for their residence is at a considerable
distance from the old nest, the ants construct some intermediate
receptacles, resembling small ant-hills, consisting of a cavity
filled with fragments of straw and other materials, in which they
form several cells; and here at first they deposit their recruits,
males, females, and brood, which they afterwards conduct to the final
settlement. These intermediate stations sometimes become permanent
nests, which however maintain a connexion with the capital city[92].
While the recruiting is proceeding it appears to occasion no sensation
in the original nest; all goes on in it as usual, and the ants that
are not yet recruited pursue their ordinary occupations: whence it is
evident that the change of station is not an enterprise undertaken by
the whole community. Sometimes many neuters set about this business at
the same time, which gives a short existence (for in the end they all
reunite into one) to many separate formicaries. If the ants dislike
their new city, they quit it for a third, and even for a fourth: and
what is remarkable, they will sometimes return to their original
one before they are entirely settled in the new station; when the
recruiting goes in opposite directions, and the pairs pass each other
on the road. You may stop the emigration for the present, if you can
arrest the first recruiter, and take away his recruit[93].
I shall now relate to you some other portions of Myrmidonian History,
which, though perhaps not so striking and wonderful as the preceding
details, are not devoid of interest, and will serve to exemplify
their incredible diligence, labour, and ingenuity.
In this country it is commonly in March, earlier or later according
to the season, that ants first make their appearance, and they
continue their labours till the middle or latter end of October. They
emerge usually from their subterranean winter-quarters on some sunny
day; when, assembling in crowds on the surface of the formicary,
they may be observed in continual motion, walking incessantly over
it and one another, without departing from home; as if their object,
before they resumed their employments, was to habituate themselves
to the action of the air and sun[94]. This preparation requires a
few days, and then the business of the year commences. The earliest
employment of ants is most probably to repair the injuries which
their habitation has received during their state of inactivity: this
observation more particularly applies to the hill-ant (_F. rufa_),
all the upper stories of whose dwellings are generally laid flat
by the winter rains and snow; but every species, it may well be
supposed, has at this season some deranged apartments to restore to
order, or some demolished ones to rebuild.
After their annual labours are begun, few are ignorant how
incessantly ants are engaged in building or repairing their
habitations, in collecting provisions, and in the care of their
young brood; but scarcely any are aware of the extent to which their
activity is carried, and that their labours are going on even in the
night.--Yet this is a certain fact.--Long ago Aristotle affirmed
that ants worked in the night when the moon was at the full[95]; and
their historian Gould observes, "that they even exceed the painful
industrious bees. For the ants employ each moment, by day and night,
almost without intermission, unless hindered by excessive rains[96]."
M. Huber also, speaking of a mason-ant, not found with us, tells us
that they work after sun-set, and in the night[97]. To these I can
add some observations of my own, which fully confirm these accounts.
My first were made at nine o'clock at night, when I found the
inhabitants of a nest of the red ant (_Myrmica rubra_) very busily
employed; I repeated the observation, which I could conveniently do,
the nest being in my garden, at various times from that hour till
twelve, and always found some going and coming, even while a heavy
rain was falling. Having in the day noticed some Aphides upon a
thistle, I examined it again in the night, at about eleven o'clock,
and found my ants busy milking their cows, which did not for the
sake of repose intermit their suction. At the same hour, another
night, I observed the little negro ant (_F. fusca_) engaged in the
same employment upon an elder. About two miles from my residence
was a nest of Gould's hill-ant (_F. rufa_), which, according to M.
Huber, shut their gates, or rather barricade them, every night, and
remain at home[98]. Being desirous of ascertaining the accuracy of
his statement, early in October, about two o'clock one morning, I
visited this nest in company with an intelligent friend; and to our
surprise and admiration we found our ants at work, some being engaged
in carrying their usual burthen, sticks and straws, into their
habitation, others going out from it, and several were climbing the
neighbouring oaks, doubtless to milk their Aphides. The number of
comers and goers at that hour, however, was nothing compared with
the myriads that may always be seen on these nests during the day.
It so happened that our visit was paid while the moon was near the
full; so that whether this species is equally vigilant and active
in the absence of that luminary yet remains uncertain. Perhaps this
circumstance might reconcile Huber's observation with ours, and
confirm the accuracy of Aristotle's statement before quoted. To the
_red ant_, indeed, it is perfectly indifferent whether the moon shine
or not; they are always busy, though not in such numbers as during
the day. It is probable that these creatures take their repose at all
hours indifferently; for it cannot be supposed that they are employed
day and night without rest.
I have related to you in this and former letters most of the works
and employments of ants, but as yet I have given you no account of
their roads and track-ways.--Don't be alarmed, and imagine I am
going to repeat to you the fable of the ancients, that they wear a
path in the stones[99]; for I suppose you will scarcely be brought
to believe that, as Hannibal cut a way for the passage of his army
over the Alps by means of vinegar, so the ants may with equal effect
employ the formic acid: but more species than one do really form
roads which lead from their formicaries into the adjoining country.
Gould, speaking of his jet-ant (_F. fuliginosa_), says that they
make several main track-ways, (streets he calls them,) with smaller
paths striking off from them, extending sometimes to the distance of
forty feet from their nest, and leading to those spots in which they
collect their provisions; that upon these roads they always travel,
and are very careful to remove from them bits of sticks, straw, or
anything that may impede their progress; nay, that they even keep low
the herbs and grass which grow in them, by constantly biting them
off[100], so that they may be said to mow their walks. But the best
constructors of roads are the hill-ants (_F. rufa_). Of these De Geer
says, "When you keep yourself still, without making any noise, in
the woods peopled with these ants, you may hear them very distinctly
walking over the dry leaves which are dispersed upon the soil, the
claws of their feet producing a slight sound when they lay hold of
them. They make in the ground broad paths, well beaten, which may be
readily distinguished, and which are formed by the going and coming
of innumerable ants, whose custom it is always to travel in the same
route[101]." From Huber we further learn, that these roads of the
hill-ants are sometimes a hundred feet in length, and several inches
wide; and that they are not formed merely by the tread of these
creatures, but hollowed out by their labour[102]. Virgil alludes
to their tracks in the following animated lines, which, though not
altogether correct, are very beautiful:
"So when the pismires, an industrious train,
Embodied rob some golden heap of grain,
Studious ere stormy winter frowns to lay
Safe in their darksome cells the treasured prey;
_In one long track_ the dusky legions lead
Their prize in triumph through the verdant mead;
Here bending with the load, a panting throng
With force conjoin'd heave some huge grain along;
Some lash the stragglers to the task assign'd,
Some to their ranks the bands that lag behind:
They crowd _the peopled path_ in thick array,
Glow at the work, and darken all the way."
Bonnet, observing that ants always keep the same track both in going
from and returning to their nest, imagines that their paths are
imbued with the strong scent of the formic acid, which serves to
direct them; but, as Huber remarks, though this may be of some use
to them, their other senses must be equally employed, since it is
evident, when they have made any discovery of agreeable food, that
they possess the means of directing their companions to it, though
it is scarcely possible that the path can have been sufficiently
impregnated with the acid for them to trace their way to it by scent.
Indeed the recruiting system described above, proves that it requires
some pains to instruct ants in the way from an old to a new nest;
whereas, were they directed by scent, after a sufficient number had
passed to and fro to imbue the path with the acid, there would be no
occasion for further deportations[103].
Though ants have no mechanical inventions to diminish the quantum of
labour, yet by numbers, strength, and perseverance they effect what
at first sight seems quite beyond their powers. Their strength is
wonderful: I once, as I formerly observed, saw two or three of them
haling along a young snake not dead, which was of the thickness of
a goose-quill[104]. St. Pierre relates, that he was highly amused
with seeing a number of ants carrying off a Patagonian centipede.
They had seized it by all its legs, and bore it along as workmen
do a large piece of timber[105]. The Mahometans hold, as Thevenot
relates, that one of the animals in Paradise is Solomon's ant, which,
when all creatures in obedience to him brought him presents, dragged
before him a locust, and was therefore preferred before all others,
because it had brought a creature so much bigger than itself. They
sometimes, indeed, aim at things beyond their strength; but if they
make their attack, they pertinaciously persist in it though at the
expense of their lives. I have in my cabinet a specimen of _Colliuris
longicollis_, Latr., to one of the legs of which a small ant,
scarcely a thirtieth part of its bulk, is fixed by its jaws. It had
probably the audacity to attack this giant, compared with itself, and
obstinately refusing to let go its hold was starved to death[106].
Professor Afzelius once related to me some particulars with respect
to a species of ant in Sierra Leone, which proves the same point. He
says that they march in columns that exceed all powers of numeration,
and always pursue a straight course, from which nothing can cause
them to deviate: if they come to a house or other building, they
storm or undermine it; if a river comes across them, though millions
perish in the attempt, they endeavour to swim over it.
This quality of perseverance in ants on one occasion led to very
important results, which affected a large portion of this habitable
globe; for the celebrated conqueror Timour, being once forced to take
shelter from his enemies in a ruined building, where he sat alone many
hours, desirous of diverting his mind from his hopeless condition, he
fixed his observation upon an ant that was carrying a grain of corn
(probably a pupa) larger than itself up a high wall. Numbering the
efforts that it made to accomplish this object, he found that the grain
fell sixty-nine times to the ground, but the seventieth time it reached
the top of the wall. "This sight (said Timour) gave me courage at the
moment; and I have never forgotten the lesson it conveyed[107]."
Madame Merian, in her _Surinam Insects_, speaking of the large-headed
ant (_Œcodoma cephalotes_), affirms that, if they wish to emigrate,
they will construct a living bridge in this manner:--One individual
first fixes itself to a piece of wood by means of its jaws, and
remains stationary; with this a second connects itself; a third
takes hold of the second, and a fourth of the third, and so on, till
a long connected line is formed fastened at one extremity, which
floats exposed to the wind, till the other end is blown over so as to
fix itself to the opposite side of the stream, when the rest of the
colony pass over upon it, as a bridge[108]. This is the process, as
far as I can collect it from her imperfect account:--as she is not
always very correct in her statements, I regarded this as altogether
fabulous, till I met with the following history of a similar
proceeding in De Azara, which induces me to give more credit to it.
He tells us, that in low districts in South America, that are exposed
to inundations, conical hills of earth may be observed, about three
feet high, and very near to each other, which are inhabited by a
little black ant. When an inundation takes place, they are heaped
together out of the nest into a circular mass, about a foot in
diameter and four fingers in depth. Thus they remain floating upon
the water while the inundation continues. One of the sides of the
mass which they form is attached to some sprig of grass, or piece
of wood; and when the waters are retired, they return to their
habitation. When they wish to pass from one plant to another, they
may often be seen formed into a bridge, of two palms length, and of
the breadth of a finger, which has no other support than that of its
two extremities. One would suppose that their own weight would sink
them; but it is certain that the masses remain floating during the
inundation, which lasts some days[109].
You must now be fully satiated with this account of the constant
fatigue and labour to which our little pismires are doomed by the law
of their nature; I shall therefore endeavour to relieve your mind by
introducing you to a more quiet scene, and exhibit them to you during
their intervals of repose and relaxation.
Gould tells us that the hill-ant is very fond of basking in the sun,
and that on a fine serene morning you may see them conglomerated
like bees on the surface of their nest, from whence, on the least
disturbance, they will disappear in an instant[110]. M. Huber also
observes, after their labours are finished, that they stretch
themselves in the sun, where they lie heaped one upon another, and
seem to enjoy a short interval of repose: and in the interior of an
artificial nest, in which he had confined some of this species,
where he saw many employed in various ways, he noticed some reposing
which appeared to be asleep[111].
But they have not only their time for repose; they also devote
some to relaxation, during which they amuse themselves with sports
and games. "You may frequently perceive one of these ants (_F.
rufa_) (says our Gould) run to and fro with a fellow-labourer in
his forceps, of the same species and colony. It appeared first in
the light of provisions; but I was soon undeceived by observing,
that after being carried for some time, it was let go in a friendly
manner, and received no personal injury. This amusement, or whatever
title you please to give it, is often repeated, particularly amongst
the hill-ants, who are very fond of this sportive exercise[112]."
A nest of ants which Bonnet found in the head of a teazle, when
enjoying the full sun, which seems the acme of formic felicity,
amused themselves with carrying each other on their backs, the rider
holding with his mandibles the neck of his horse, and embracing it
closely with his legs[113]. But the most circumstantial account of
their sports is given by Huber. "I approached one day," says he, "one
of their formicaries (he is speaking of _F. rufa_) exposed to the sun
and sheltered from the north. The ants were heaped together in great
numbers, and seemed to enjoy the temperature which they experienced
at the surface of the nest. None of them were working: this multitude
of accumulated insects exhibited the appearance of a boiling
fluid, upon which at first the eye could scarce fix itself without
difficulty. But when I set myself to follow each ant separately, I
saw them approach each other, moving their antennæ with astonishing
rapidity; with their fore-feet they patted lightly the cheeks of
other ants: after these first gestures, which resembled caresses,
they reared upon their hind-legs by pairs, they wrestled together,
they seized one another by a mandible, by a leg or an antenna, they
then let go their hold to renew the attack; they fixed themselves to
each other's trunk or abdomen, they embraced, they turned each other
over, or lifted each other up by turns--they soon quitted the ants
they had seized, and endeavoured to catch others: I have seen some
who engaged in these exercises with such eagerness, as to pursue
successively several workers; and the combat did not terminate till
the least animated, having thrown his antagonist, accomplished his
escape by concealing himself in some gallery[114]." He compares these
sports to the gambols of two puppies, and tells us that he not only
often observed them in this nest, but also in his artificial one.
I shall here copy for you a memorandum I formerly made. "On the ninth
of May, at half-past two, as I was walking on the Plumstead road near
Norwich, on a sunny bank I observed a large number of ants (_Formica
fusca_) agglomerated in crowds near the entrances of their nest.
They seemed to make no long excursions, as if intent upon enjoying
the sun-shine at home; but all the while they were coursing about,
and appeared to accost each other with their antennæ. Examining them
very attentively, I at length saw one dragging another, which it
absolutely lifted up by its antennæ, and carrying it in the air. I
followed it with my eye, till it concealed itself and its antagonist
in the nest. I soon noticed another that had recourse to the same
manœuvres; but in this instance the ant that was attacked resisted
manfully, a third sometimes appearing inclined to interfere: the
result was, that this also was dragged in. A third was haled in
by its legs, and a fourth by its mandibles. What was the precise
object of these proceedings, whether sport or violence, I could not
ascertain. I walked the same way on the following morning, but at an
earlier hour, when only a few comers and goers were to be seen near
the nest:" And soon leaving the place, I had no further opportunity
to attend to them.
And now having conducted you through every apartment of the
formicary, and shown you its inhabitants in every light, I shall
leave you to meditate on the extraordinary instincts with which their
Creator has gifted them, reserving what I have to say on the other
social insects for a future occasion.
I am, &c.
FOOTNOTES:
[35] It is not here meant to be asserted that insects are actuated by
these passions in the same way that man is, but only that in their
various instincts they exhibit the semblance of them, and as it were
_symbolize_ them.
[36] Plusieurs d'entre eux (_Insectes_) savent user de ressources
ingénieuses dans les circonstances difficiles: ils sortent alors de
leur routine accoutumée et semblent agir d'après la position dans
laquelle ils se trouvent; c'est là sans doute l'un des phénomènes les
plus curieux de l'histoire naturelle. Huber, _Nouvelles Observations
sur les Abeilles_, ii. 198.--Compare also ibid. 250, note N. B.
[37] I employ occasionally the term _neuters_, though it is not
perfectly proper, for the sake of convenience;--strictly speaking,
they may rather be regarded as imperfect or sterile females. Yet
certainly, as the imperfection of their organization unfits them for
sexual purposes, the term _neuter_ is not absolutely improper.
[38] _Œuv._ ix. 163.
[39] M. P. Huber in _Linn. Trans._ vi. 256. Reaum. v.
[40] VOL. I. 244.
[41] The neuters in all respects bear a stronger analogy to the larvæ
than to the perfect insects; and, after all, may possibly turn out
to be larvæ, perhaps of the males. Huber seems to doubt their being
neuters. _Nouv. Obs._ ii. 444, note *.
[42] In this these animals vary from the usual instinct of the social
_Hymenoptera_, the ants, the wasps, and the humble-bees--with whom
the females lay the first foundations of the colonies, unassisted
by any neuters;--but in the swarms of the hive-bee an election may
perhaps in some instances be said to take place.
[43] VOL. I. Ed. 508.
[44] See VOL. I. 509.
[45] Gould's _Account of English Ants_, 22.
[46] The late John Hunter dissected two young queens. In the abdomen
he found two ovaries, consisting of many hundred oviducts, each
containing innumerable eggs.
[47] The anonymous author before alluded to, who observed the Ceylon
white ants, says, that such was the size of the masses, which were
tempered with a strong gluten, that they adhered though laid on the
upper part of the breach.
[48] Latr. _Hist. Nat._ xiii. 64.
[49] _N. Dict. D'Hist. Nat._ xxii. 57, 58.
[50] Bochart, _Hierozoic._ ii. 1. iv. c. 22.
[51] M. P. Huber, in the account which, in imitation of De Geer,
he has given of the discoveries made by his predecessors in the
history of ants, having passed without notice, probably ignorant of
the existence of such a writer, those of our intelligent countryman
Gould, I shall here give a short analysis of them; from which it will
appear, that he was one of their best, or rather their very best
historian, till M. Huber's work came out. His _Account of English
Ants_ was published in 1747, long before either Linné or De Geer had
written upon the subject.