These little creatures are probably the most intelligent of all the
insects--and yet at times they seem to wander about almost aimlessly. A
worker may be found with an insect or something which it is eagerly
dragging along and drops probably from fear. It appears anxious to regain
its hold of it, but goes about in all sorts of wrong directions before it
again finds it, it may be to make sure its enemy is clear away before it
resumes operations, but the effect to the ordinary onlooker is one of sheer
incapacity--at the same time the wonderful habits of the tribe, the way in
which they keep plant lice for their larvae, their methods of carrying each
other, their nest-building, and the slave-making instincts of some of the
species, show an intelligence surpassed by no other family of insects.
Their nests are formed in very various ways: the same species even will
sometimes nest under a stone and sometimes make ant hills; some {32} of the
large species make their nests of huge heaps of fir needles, and number 400
to 500 thousand in one nest--others live in quite small communities,
nesting in bramble stems, old rotten wood, moss, etc. One little species,
rare with us, lives in the walls of other ants' nests, just as mice live in
the walls of our houses; another quite small species lives apparently on
friendly terms with the common large red or horse ant, and may be found
running about amongst them, on and in their nests, but, so far as I know,
nothing is known as to how its young are reared. There is a curious
division in the family between the ants that have true stings and those
which have not. The large ants of our fir woods can bite and are able to
eject poison through the apical opening of the body into the wound they
create, but these as well as the larger and smaller black ants and some
others have the sting undeveloped, whereas some of our small species have a
sting which they can use with considerable effect; this difference in habit
is accompanied by a difference in the structure in the basal segments of
the body. In the stingless species the basal segment is reduced {33}
[Illustration: FIG. 6] to a flat upright transverse scale (fig. 6, 1); in
the stinging ants two segments at the base are reduced to nodes (fig. 6,
3). There is an exception in the case of one little rare genus, _Ponera_,
which has only the basal abdominal segment reduced to a scale although a
much thicker scale than in the others (fig. 6, 2), and yet which has a
distinct sting. These arrangements give the body very free movement so that
the tail can be bent forward till it reaches the head. Another curious
distinction between the stingers and non-stingers is that the larvae of the
former spin cocoons and those of the latter do not; the larvae of _Formica
fusca_ occasionally do not do so, but they are an exception to the rule.
Cocoon spinning seems to involve the larvae in some difficulties, as
without the help of the worker ants they are often unable to extract
themselves from their prison. This is a condition which does not, I
believe, exist in other groups. In the stingless ants there is a curious
difference in habit between the {34} species of the genus _Formica_, where,
according to Forel, the workers do not follow in line over unknown ground,
and frequently carry one another, the one carried being rolled up under the
head of the other, and the species of _Lasius_, where the workers follow
one another in line, but never carry each other. Among the stinging ants
another method of carrying occurs in certain genera. The porter seizes the
one she wishes to carry by the external edge of one of her mandibles and
then throws her over her back, so that she lies along the back of her
porter with her ventral aspect uppermost and her legs and antennae folded
as in the nymph state. Neither of these methods sounds very comfortable,
but then probably an ant's idea of comfort and our own may be very
different.
Lord Avebury, in his _Ants, Bees and Wasps_, tells us that he has known a
male of _Myrmica ruginodis_ live for nine months, although no doubt, as he
says, they generally die almost immediately, and he has known queen ants to
live for seven years, and workers, which he had in his nest, for six years.
* * * * *
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