Ants Are Ecologically Beneficial

Encyclopedia Article

In Defense of Ants

Ants seem to be the Rodney Dangerfields of the insect world.  They “don’t get no respect.”  Everybody hates them and some people really HATE them!  Here are qualities and benefits of ants that should earn them some respect.

In an optimistic attempt to reduce this bias against ants, I offer the following lesson in myrmecology.

From a small handful of ant scientists in the world, thousands of naturalists, ecologists and other careful observers, we have learned an immense amount about ants, the rivals of humans as the dominant life form on the earth.  Ants are exceedingly abundant and are found almost everywhere.  By one estimate, if you combined all the ants of the world they would weigh about as much as the combined weight of all the humans.

And, ants are survivors.  They are adaptable, resourceful and highly specialized to survive in the circumstances in which they exist.  Ants have been on the earth since the middle of the Cretaceous Period, or about 80 million years, which means they survived the mass extinction of 65 million years ago that eliminated the dinosaurs.  There are approximately 14,000 different known species (with the possibility of thousands more species yet to be discovered) that cover the terrestrial surface of the earth from the arctic circle to Tierra del Fuego and southern Africa.

You need not worry that 14,0000 different kinds of ants will live in your backyard in Iowa since the majority of species live in limited areas of the tropics.  The estimated number of different kinds of ants in North America (north of Mexico) is a mere 700 species.

Profoundly important insects

It is hard to imagine any other insect or animal that has a more important and positive impact on the terrestrial environment that sustains us.  Ants are among the leading predators of other insects, helping to keep pest populations low.  Ants move approximately the same amount of soil as earthworms, loosening the soil in the process and increasing air and water movement into the ground.  They keep the ecosystem clean of dead insect carcasses and aid in the destruction and decomposition of plant and animal matter.  By carrying bits of plants and animal remains into their nests, the soil is fertilized and nutrients recycled through the world’s ecosystems.  They carry seeds and help plants disperse into new areas.

Ants are social insects, a fact that may explain a great deal of their success.  Ants, like some bees, some wasps and all termites, live in complex societies defined by three characteristics: the adults care for the young; there are two or more generations of adults in the same nest; and there is a division of labor, specifically with numerous nonreproductive workers providing for reproducing royalty.  The advantage of a social life is probably greatest as insects compete with each other and with other life forms for territory and food.

The ants have a complete life cycle of 4 stages: egg, larva, pupa and adult.  Most people are familiar only with the adult, the lone stage to exist outside of the colony nest.  Eggs are produced only by the select few queens.  The eggs hatch into wrinkled, white, legless grubs (larvae) that must be nurtured by adult ants in order to survive.  The nonreproductive adults (workers) scour the vicinity of the nest for living or dead insects, nectar, plant matter or other food appropriate to the species and bring it back to feed the helpless larvae.  After several weeks as a larva the individual forms a protective silk cocoon and makes the transformation to the adult stage.

Almost all of the adults will emerge as sterile, wingless females.  These workers set about doing the manual labor of the colony, cleaning and enlarging the nest, foraging for food, feeding and caring for the larvae, and defending against invaders.  When the colony is well established and sufficiently vigorous, a different group of adults will emerge.  These sexually developed, winged males and females are called swarmers. They depart from the established colony to initiate new colonies with very, very slim chances of success.  But just enough succeed to spread the species and insure its survival.

Our obsession with the small number of ants that become “pests” has lead us to hold all ants in utter contempt. Yet, there is much about ants that should inspire us.  They are trustworthy, thrifty, loyal and brave.  They are industrious and provide tremendous benefit to their community (ecosystem).  They are selfless in service to their colony and devotion to their family.  Ants function with astounding efficiency and complexity that is simultaneously bewildering and predictable. And finally, no matter how hard they work, they still have time to go to a picnic!

Do you live in Iowa and have an insect you would like identified?

The Iowa State University Plant & Insect Diagnostic Clinic will identify your insect, provide information on what it eats, life cycle, and if it is a pest the best ways to manage them.  Please see our website for current forms, fees, and instructions on preserving and mailing insects.   

Contact information for each states diagnostic laboratory for U.S. residents.  If you live outside of Iowa please do not submit a sample without contacting the Plant & Insect Diagnostic Clinic

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