The ant society
Both ants and termites (white ants) live in large colonies consisting
mostly of sterile, wingless workers, dedicated to the efficient production of
winged reproductive castes which fly off to found new colonies... Both ant and
termite colonies have one enlarged 'queen', sometimes grotesquely enlarged.
In both ants and termites the workers can include specialist castes such as
soldiers. Sometimes these are such dedicated fighting machines, especially in
their huge jaws (in case of ants, but 'gun-turrets' for chemical warfare in
the case of termites), that they are incapable of feeding themselves and have
to be fed by non-soldier workers....
Terror of the jungle?
Both driver ants and army ants have exceptionally large colonies, upto a
million in army ants, up to about 20 million in driver ants. Both have
nomadic phases alternating with 'statary' phases, relatively stable
encampments or 'bivouacs'. Army ants and driver ants, or their colonies taken
together as amoeba-like units, are both ruthless and terrible predators of
their respective jungles. Both cut to pieces anything animal in their path,
and both have acquired a mystique of terror in their own land. Villagers in
part of South America are reputed traditionally to vacate their villages,
lock, stock and barrel when a large ant army is approaching, and to return
when the legions have marched through, having cleaned out every cockroach,
spider and scorpion even from the thatched roofs. I remember as a child in
Africa being more frightened of driver ants than of lions and crocodiles...
No, driver ants are not really the terror of the jungle. Although the driver
ant colony is an 'animal' weighing in excess of 20 kg and possesssing on the
order of 20 million mouths and stings and is surely the most formidable
creation of the insect world, it still does not match up to the lurid stories
told about it. After all, the swarm can only cover about a meter of ground
every three minutes. Any competent bush mouse, not to mention man or
elephant, can step aside and contemplate the whole grass root frenzy at
liesure, an object less of menace than of strangeness and wonder...
The strangeness and wonder
As an adult in Panama I have stepped aside and contemplated the New
World equivalent of the driver ants that I had feared as a child in Africa,
flowing by me like a crackling river, and I can testify to the strangeness
and wonder. Hour after hour the legions marched past, walking as much over
each others' bodies as over the ground, while I waited for the queen. Finally
she came, and hers was an awesome presence. It was impossible to see her
body. She appeared only as a moving wave of worker frenzy, a boiling
peristaltic ball of ants with linked arms. She was somewhere in the seething
ball of workers, while all around it the massed ranks of soldiers faced
threateningly outwards with jaws agape, every one prepared to kill and to die
in defence of the queen. Forgive my curiosity to see her : I prodded the ball
of workers with a long stick, in a vain attempt to flush out the queen.
Instantly 20 soldiers buried their massively muscled pincers in my stick,
possibly never to let go, while dozens more swarmed up the stick causing me
to let go with alacrity.
I never did glimpse the queen, but somewhere inside that boiling ball she was, the central data bank, the repository of the master DNA of the whole colony. Those gaping soldiers were prepared to die for the queen, not because they loved their mother, not because they had been drilled in the ideals of patriotism, but simply because their brains and their jaws were built by the genes stamped from the master die carried in the queen herself. They behaved like brave soldiers because they had inherited the genes of a long line of ancestral queens whose lives, and whose genes, had been saved by soldiers as brave as themselves. My soldiers had inherited the same genes from the present queen as those old soldiers had inherited from the ancestral queens. My soldiers were guarding the master copies of the very instructions that made them do the guarding. They were guarding the wisdom of their ancestors, the Ark of the Convent.
- Richard Dawkins in "The Blind Watchmaker"
S. Daugerri - a parasite ant
Once introduced into the fire ant nest, S. Daugerri directly attacks the
queen, clamping onto her antenna, legs, or thorax. You'd think the (fire ant)
workers would rip them to pieces. But they don't, because the parasite mimics
the queens pheromones - the chemical recognition signals insects use to
communicate. The hornswoggled workers then devote their efforts to feeding
the parasites, half a dozen of which might yoke the queen. Eventually the
queen starves to death in full view of the workers who serve her... The
prospect of worker ants happily starving their queen to death is sure to
bring a smile to the millions of people who have experienced the nasty sting
of the fire ant.
- Science, vol. 263, page 1561 (March 1994)