By Marcia Anderson
Remember the ant marching song: “…The ants go marching two by two hurrah, hurrah…” The ants are lining up to enter classrooms around the country, eagerly following our children. Why? Why are ants the most common insects found in schools? Ants do not attend class for the math lesson. They could care less about multiplication, dividends or square roots. The dividends they are looking for are the crumbs students have dropped or left in their desks. With the holidays around the corner, many schools celebrate with food and special treats. If ants cannot find food, they will march on to, perhaps the kitchen or other classrooms.
It is important to recognize that most ants can be both beneficial and pests. Most ants are not a serious threat to human health or property, with the exception of carpenter ants (or fire ants in southern states). Ants provide an important ecological cleansing and fertilization service by aerating the soil outdoors and recycling dead animal and vegetable material. Ants also kill numerous pest insects, including fly larvae, termites, fleas, and caterpillars. Ants become pests when they invade school buildings searching for food and water to take back to their nests.
Before taking any action against an invading ant, be sure there is more than one ant present. Just one may have hitchhiked in on food packaging, clothing, or a backpack that had been placed on the ground for a while outside. Multiple worker ants (those without wings) suggest a nearby nest and an entrance hole. Take a few minutes to watch the ants. Where are they going? Where did they come from?
Did you know that there are approximately over a quadrillion ants alive in the world at any one time, or about one million ants for every human on earth? So it is neither desirable nor practical to try to eliminate most ants from their outside habitat.
Ant control. Management efforts should aim at keeping them out of structures as part of a smart, sensible, and sustainable approach to pest control called Integrated Pest Management or IPM. Ant control should focus on excluding ants from the building, good sanitation, and building maintenance rather than routine spraying with pesticides, which may not always be effective. Ant management requires continuous effort.
Inspection and Detection. Often it takes detective work and ingenuity to discover where ants are coming from. When you spot large numbers of ants in a trail, try to follow the ants to where they are entering the building. Carry a good flashlight. Take good notes during your inspection and record problem areas, entry locations and areas needing repair. If a nest is found inside, it must be removed. Call your IPM coordinator or a pest management professional for help. To do it yourself, use an industrial vacuum, and vacuum up some cornstarch to prevent ants from escaping, then seal and destroy the vacuumed material.
Habitat modification: Exclusion. By carefully sealing places where ants enter, you will make a long-term impact on the number of ant invasions. Begin with sealing actual and potential entryways – especially where wires and pipes enter the building, then weather-strip around doors and windows. Always carry a tube of sealant when making inspections and seal as many cracks as time allows, especially those around baseboards, pipes, sinks, toilets, and electrical outlets. Silicone sealant is flexible, easy to apply, and long-lasting. Keep plants and mulch away from the foundation of buildings as they provide ant nesting sites.
For more information on ant control in schools go to: http://www.sites.ext.vt.edu/schoolipm/ipmtechniques/documents/ants.pdf and look for more information in a future blog.
About the Author: Marcia is with EPA’s Center of Expertise for School IPM in Dallas, Texas. She holds a PhD in Environmental Management from Montclair State University along with degrees in Biology, Environmental Design, Landscape Architecture, and Instruction and Curriculum. Marcia was formerly with the EPA Region 2 Pesticides Program and has been a professor of Earth and Environmental Studies, Geology, and Oceanography at several universities.