Summary: Army ants travel in a bivouac, or swarm while they search for food. They are migratory insects and do not like to stay in one place for a long period of time. They are interesting insects to observe because they are almost entirely dependent on each other.
Scientific research has proven that though there are many different types of Army ants (about 150 different species), they evolved from one original ancestor. In fact, this ancestor was roaming the earth 100 million years ago. The original Army ant is so ancient that it lived before modern-day continents broke apart thriving on a super-continent known as Gondwana, a composite continent, made up of South America, Africa, Madagascar, Antarctica, India, other parts of South Asia, and Australia. At one time it even included Florida and most of Southern Europe. Today, Army ants are readily found in warm, wet tropical areas. If you vacation anywhere south of Florida, you may see army ants. Some species live in the United States, but primarily in southern areas with warmer climates, such as Texas and southern California.
Army ants are different than other types of insects because they are migratory. However, these brown or yellow ants occasionally stop to bivouac, or nest for a short period of time, so that the queen can lay her eggs. Strangely enough, the bivouac is made up of the army ant bodies. They gather tightly together to form the bivouac in order to fully protect the queen. When the ants return to the migratory stage, they will typically move to a different nesting place every night for about two weeks.
Some interesting Army ant behaviors include their ability to form bridges with their bodies to overcome obstacles such as streams or valleys. They also have the ability to send out search parties for food while the rest of the ants continue marching forward barricading and protecting the queen.
The Army ant queen can mate only once with a male worker ant, if it so chooses, and will continuously lay eggs every three weeks. A queen can lay about four million eggs per month. Usually, the queen will not mate more than five times during its life. The male Army ants that the queen mates with will lose their wings and die about two days after mating.
Army ants eat many kinds of insects and animals including snakes, lizards and scorpions, plus much larger animals including pigs, chickens and goats. Some species of Army ants may eat over 100,000 insects per day. Their voracious appetites for insects should make these ants beneficial insects, but because they travel in swarms, they clearly cause more damage than good.
How to Avoid Army Ant Infestation:
¢ Keep your house clean on a regular basis. Ants are attracted to places in which they can hide easily and obtain food.
¢ Replace ripped screens in windows and doors immediately. Even small tears are big enough to allow ants to crawl in.
¢Fix any crevices or cracks in the foundation or siding of your home.
¢ Avoid putting mulch against the side of your home.
¢ Trim back any shrubs or branches of trees touching your house.
How to Handle Army Ant Infestation:
¢ If you see Army ants crawling around, scoop them up with a soapy sponge.
¢ Caulk any holes by doors or windows to avoid letting more Army ants inside.
¢ Plug up the drains in your sinks and bathtubs at night.
¢ If the infestation is out of control, spraying insecticide directly on the ants should help.
¢ If Army ants are crawling inside hollow walls, drill some small holes into the walls. Then, treat with an aerosol insecticide.
¢ Make every effort to find the bivouac and eliminate it. Killing individual ants will help, but it will not fix the problem. If you cannot find the bivouac, call a professional exterminator to assist.