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ANTS
Ants are some of the most successful animals on Earth. They are
found in jungles and deserts, on mountains and in valleys, at
beaches and on prairies, in cities and on farms. Some live in
trees, some in wood, one kind in acacia-tree thorns, but most
live in the earth. Ants never live on their own—they are
social insects, living in families of hundreds or hundreds of
thousands. The individual ants in a colony are so dutiful to its
operation that some observers have suggested that the individual
ants act more like cells in an organism than like individual free-living
organisms.
Ants develop with complete metamorphosis. All of the ants in
a colony are sisters because they all come from a single mother,
the queen, that was fertilized as a result of mating once in her
life. This single egg-laying factory will produce all of the workers
for a colony for up to several years. After the eggs are laid,
workers nurture them until they develop into new workers. Workers
feed the larvae until they pupate. If the temperature climbs or
drops out of the optimal range for the development of the new
generation, workers move the eggs, larvae, and pupae to locations
in the colony where conditions are better. If you flood the garden
or roll over a rock, you might see a hoard of ants sally forth,
carrying little white packages. These are workers carrying the
larvae and pupae to safer or dryer quarters.
Much could be said about these incredible animals—their
aphid herding, leaf cutting, mushroom growing, sugar processing,
mound building, and life cycle—but most of it is observable
only on video or in the pages of natural history books. One thing
that can be observed easily in the classroom and that will thrill
students is tunneling. The classic ant farm with two sheets of
clear plastic separated by about 2 cm (1"), filled with sand
or some other material that is easily tunneled, can provide hours
of interest. You will probably be able to obtain only worker ants,
so there is no potential for establishing a permanent colony,
but for the brief 3 or 4 weeks that the workers in the farm are
alive, they will tunnel and retunnel with boundless zeal. Students
will be able to appreciate the monumental strength of ants and
see how they constantly communicate with one another by touching
antennae.
Ants look quite different from the other insects discussed up
to this point in the module. They have bulbous abdomens narrowly
attached to the thorax, and substantial jaws that are in many
cases capable of delivering a powerful pinch and a potent injection
of venom. Even so, ants display the unmistakable characteristics
of an insect—three body parts and six legs emanating from
the thorax.
Purchase an ant farm. Ant farms are sold
by toy stores, educational supply companies, and biological supply
companies. They are straightforward to set up following the directions
that accompany them. Ants do not come in the box—you must
send in a coupon and expect delivery 1–2 weeks later. See
the Materials folio for more information about ordering insects.
What to do when the ants arrive. It is important
to place the ants in the farm as soon as they arrive because they
will need food and water after their trip in the mail. You should
have your ant farm assembled with the sand in place.
Discuss ants with students and show the farm a few days before you anticipate the arrival of the ants. The day they arrive, add water as described in the farm instructions and food as described in the ant package, and the ants can be put into the farm without delay.
The two dozen or so ants that arrive will all be workers of varying
ages. Because ant workers live relatively short lives, they will
start to die soon after being placed in the farm. It is interesting
to see what the workers do with their fallen companions. Some
ants will live for a month or so, after which time you can put
the ant farm away for awhile, or resupply the farm from the commercial
source.
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