Field ants are the type of ants mostly noticed in the garden. They are mostly seen in the fall when it is the mating season. While the ants are harmless, they will emerge from underground colonies in large numbers. This is quite off putting and demands the attention of proper pest control.
The ant species referred to as “field ants” are known to inhabit lawns, meadows and fields. In some ways, they can be seen as benefits because they offer a source of food to plant pests (mealy bugs, aphids, etc.), termites, silverfish, moths and bed bugs. But, similar to other pests, they will soon become a problem after invading your private space in numbers.
Problems with field ants
The field ants can cause a variety of problems. For instance, they can easily build soil heaps on the lawns that span 4-feet in diameter or more. The typical height is generally less than the height of the grass blades. But, there are others that can easily reach 2-feet or more in height. Stacks of firewood can be enticing to field ants. They are known to build a nest inside the wood, so extra caution is needed for those planning to take the wood in the home. Even though rare, there is also the risk of the ants entering the home in an attempt to find food.
Identifying field ants
Field ants are not equipped with a stinger, but they can pinch and puncture the skin when disturbed and inject formic acid. Formic acid can also be used to kill and remove plants that are giving shade to their mounds.
The field ants vary significantly in relation to color and size (even applies to a single species of the field ants). The size of the ants range from 1/5 inch to 3/8 inch and standard colors are tan, black, brown and red. However, there are also two-colored species. Plus, the large field ants are easily mistaken for the carpenter ants.
Damage caused by field ants
Field ants are known to create large and unsightly mounds of soil on the lawn. While the damage isn’t permanent and easily repaired, the injection of acid into localized plants is likely to have long-term impact. Also, the ants are likely to attack people or pets if the mounds are disturbed.
A fully established colony has the potential to last 10 years or more, so the use of appropriate ant control is likely to be necessary.
How to Control field ants
For the actual ants starting to cause problems in or around the home, the most practical control method is to directly attack the nest.
General guidelines issued by the Clemson University College of Agriculture, Forestry and Life Sciences include:
- Use a proper pesticide intended to control field ants. Give a healthy and complete soaking of the ant mound. By completely saturating the mound, it is possible to penetrate deep beneath the surface. The queen is quite deep and likely to live 2 or 3-feet below the surface. Killing the queen is the only sure way to destroy the colony.
- If applicable, use a high volume of water to guarantee the water/insecticide penetrates the ant nest.
- Wait 2 or 3 days for the insecticide to work. Plenty of worker ants will need time to return to the nest having spent time foraging in the local area.
- Use exclusion methods to prevent ants from entering the home. This involves sealing or repairing cracks or gaps at potential entry points. Inspect the outside walls for openings by the window and door frames, as well as wiring and pipework entering the home.
- Spray a labeled non-repellent insecticide around the perimeter of the home. Use it on the wall surfaces of the foundation, while also treating windows, doorways, and under the siding.
The preferred method is the use of an application specific ant insecticide that includes active ingredients like permethrin, carbaryl (Sevin), bifenthrin, deltamethrin or cyfluthrin. The best ant killer can help you to easily control them.
Other treatment methods mentioned include the use of borax and water to eliminate ant nests, but this isn’t seen as entirely effective by the University of Wisconsin Extension Service.