that the ants react suddenly, as though in response to a signal. At a
precise instant during this particular day, they become very active
and start to bustle about. The workers leave the nest and patrol
the environs. To the eye of the experienced entomologist, it is
clear from this behaviour that the departure is imminent. Then
suddenly the males fly off, followed about twenty minutes later
by the females, the twin operations being perfectly synchronized.
In grasslands where there are several nests, the departures happen
simultaneously.
In some species, the females do not fly far, but stay close to the
nest. Some of them even stay on the ground where they emit
chemical signals, the sexual pheromones, to attract their part-
ners. In some other species, however, the young queens climb to
about a hundred feet, and the most adventurous go even higher
to find a partner. Some mate with a single male, some with
several or, in certain species, even more than ten.
The males are lucky to mate with any female; and if they
succeed, there is little likelihood that they will be able to couple
more than once, their reserves of sperm, formed when they were
still in the larval stage, being limited, because as they reach
adulthood, their testes completely degener ate.
In any case, neither those who do manage to reproduce, nor
the unlucky ones who failed to mate, will survive their nuptial
ballet. More often than not, they are unable to feed. The sugar
reserve which they have accumulated during their time in the nest
enables them to fly about for an hour at the most. They then fall
to the ground exhausted, as though they have r un out of petrol.
Some ants do this in huge numbers, for example those living in
eastern regions of the United States, where the mass demise of
the unsuccessful candidates for reproduction can be witnessed
every year at the end of the summer. This is the season of the
clouds of Lasius neoniger that Americans call ‘Labor Day ants’,
which are always reproductively active in the days just before or
after the public holiday on the first Monday in September. Once
THE LIVES OF ANTS
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