The Workings of a Fire Ant Colony
Fire ant colonies can be populated by hundreds to thousands of members. Like the individual ants, the colonies will also pass through various cycles. For instance, a new colony will not have an obvious mound for the first few months, until it gets well established.
Older and more mature colonies will have mounds of up to three feet across. As the mounds or colonies grow in size, the fire ants will become more and more territorial and will defend their territory aggressively.
The typical fire ant mound can be found in open areas that are sunny. They are unlike other ant mounds in that they will not have a visible opening. Lawns, pastures, and fields are ideal places for fire ants to build their colonies. It is not unusual to find from 20 to more than a 100 mounds in a single acre.
Mounds are built by the worker caste, with soil that is excavated from chambers far beneath the surface. This dirt is more than tunnel waste - it seals off the mass of tunnels found in a typical ant colony. As the sun warms the ground, the mounds will warm much faster and the colony moves into the mound, bringing their brood with them, to thrive on the heat of the day.
The ground is not the only place to find fire ant colonies. They have been known to take up residence in rotting logs, at the base of trees, or hidden under paved areas. At times so much soil has been removed by the ants from underneath roads that the roads actually form sink holes. Strangely enough, fire ant colonies have also been found on roofs, under debris on roofs or in electrical receptacles or boxes. They have an attraction to electrical impulses and like to live among wires, eating away at insulation and wire coverings. This often causes damage to electrical devices and power supplies.
Fire ants will tunnel deeper into the ground when it is very hot, trying to find relief from the heat and/or looking for water. It may appear that there are no ants in the mound. But after a heavy rain, disturbing the mound or drenching the mound will show you otherwise. A good way to see if there is an active colony in a mound is to simply place food, such as a potato chip or a piece of meat, near the mound. You should soon see workers coming to forage for their new find.
Colonies are made up of workers and a queen. During some parts of the year, it may also contain males and females that are referred to as "reproductives." These particular ants possess wings and will eventually take flight and reproduce to start new colonies. An average colony can contain somewhere between 100,000 to 500,000 workers, several hundred winged ants and a number of queens. A mature colony can produce up to 4,500 reproductives in a year's time. The mating flights take place six to ten times a year.
Reproductives:
The mating takes place 300 to 2000 feet in the air when temperatures are between 70 and 95 degrees, the humidity is near 100% and the wind is calm. A male reproductive has the sole responsibility to mate with the queen to keep the species alive. Male ants simply mate and then die, but the females will return to the ground after flying approximately two to three miles. They then remove their wings, locate a suitable area for nesting, and begin digging and laying eggs.
Initially the nest will be a two to five inch vertical tunnel. Interestingly, almost 99.9% of all females die before they can select a site for nesting. This is due to poor landing sites or predators. The female fire ant will next seal the tunnel for about 30 days, until the eggs begin to hatch. The nest will then be opened and worker fire ants will begin foraging for food, rearing other workers, and tending to the queen's needs.
However, that's not the only way that new colonies get started. One study conducted by University of Texas-Austin post-graduate students found some interesting facts about the spread of fire ants. In the study students dug up nests and carefully separated the queens from the other ants. Each queen was then ‘tagged’ with an ultra thin colored wire that was tied around the ant’s waist. This would allow the students to readily identify the ants. The marked queens were then placed back into their environment. It was found that ant colonies were surprisingly also spread by a method called ‘budding.’ This meant they are different from other ant species that required a queen to move on and starts a new nest. Instead, the imported fire ant colony would advance with several queens and a host of workers that would pack up and move out to start a new colony.
The Queen:
The queen is the largest ant in the colony. Her primary responsibility is to lay eggs. A typical queen will produce between 1,500 to 1,600 eggs per day. The queen's lifespan is about seven years long.
Workers will diligently and aggressively protect the queen. If the mound is disturbed in any way, the worker ants will instantaneously swarm on top of the mound for approximately eight minutes, assuring that nothing enters the mound.
If the disturbance continues, the workers then quickly escort the queen safely through underground tunnels, where she then can start a new colony. Note that some colonies are so big that there will be numerous queens within a single colony, with some having over a hundred in a single colony.
Workers:
The workers are sterile ants who...work. They build and repair the nest, care for the young, defend the nest, and feed both the young and adult ants. The workers do not live longer than one season.
Fire ant workers are different from other ant species in that they do not forage extensively above the ground, but travel through underground tunnels to reach food sources. A worker fire ant’s duties differ depending on their size, but all of their duties more or less overlap. Age is also a determining factor in the worker's duties. As the worker ant ages, they will move from taking care of the brood in the central chambers to much more general type duties away from the central area. They continue to move further and further toward the outside tunnels until their final weeks of their life, when they will then leave the nest to forage for food and eventually die.
Reproductives:
The mating takes place 300 to 2000 feet in the air when temperatures are between 70 and 95 degrees, the humidity is near 100% and the wind is calm. A male reproductive has the sole responsibility to mate with the queen to keep the species alive. Male ants simply mate and then die, but the females will return to the ground after flying approximately two to three miles. They then remove their wings, locate a suitable area for nesting, and begin digging and laying eggs.
Initially the nest will be a two to five inch vertical tunnel. Interestingly, almost 99.9% of all females die before they can select a site for nesting. This is due to poor landing sites or predators. The female fire ant will next seal the tunnel for about 30 days, until the eggs begin to hatch. The nest will then be opened and worker fire ants will begin foraging for food, rearing other workers, and tending to the queen's needs.
However, that's not the only way that new colonies get started. One study conducted by University of Texas-Austin post-graduate students found some interesting facts about the spread of fire ants. In the study students dug up nests and carefully separated the queens from the other ants. Each queen was then ‘tagged’ with an ultra thin colored wire that was tied around the ant’s waist. This would allow the students to readily identify the ants. The marked queens were then placed back into their environment. It was found that ant colonies were surprisingly also spread by a method called ‘budding.’ This meant they are different from other ant species that required a queen to move on and starts a new nest. Instead, the imported fire ant colony would advance with several queens and a host of workers that would pack up and move out to start a new colony.
Sources and Useful Links::
http://www.safe2use.com/pests/fireants/fireants2.htm
http://pctonline.com/articles/article.asp?ID=1120&IssueID=7
http://www.utexas.edu/opa/news/2006/09/biology20.html
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