How to Treat Little Fire Ants Around Your Home

Baits are an attractive food laced either with a toxin (usually a very small amount) or an insect growth regulator (IGR). Most baits for control of Little Fire Ants (LFA) come in a granular form made from corn grits to make them easier to spread. LFA feed on the bait, return to the nest leaving a trail for other worker ants to follow, and then regurgitate the bait to share with the rest of the colony.

Two types of ant baits:

1. Toxicant Baits – Made with a very small amount of slow-acting toxin so ants have time to make their way back to the nest and share the bait with other members of the colony before they are killed within 72 hours. Toxic bait products include Amdro®, Antixx®, Probait®, Siesta™, Maxforce Complete®, Advion® WDG.
   
   
2. Insect Growth Regulator Baits – Work by preventing ant young from developing into adults, but have no effect on adult worker ants. It also prevents or slows down egg production by the queen. Ant colonies baited with an IGR slowly die out over a period of months as worker ants die from natural causes and are not replaced by new workers. IGR products include Tango™.

Baits are the recommended first-line treatment because they are very effective and also minimize the use of pesticides.

Barrier treatments are insecticides that come in liquid or granular form and are sprayed or sprinkled around areas where ants are to be excluded. As ants and other insects crawl over the treated areas, they come into contact with the toxin and are killed. Barrier treatments usually have a residual activity and can provide protection for months.

Granular barrier treatments can be spread using a simple seed spreader, just like baits. However, it is good practice to have 2 spreaders – one for use with baits and the other for the barrier treatment (mark each one with a marker pen so you know which is which). If you use the same spreader for both jobs, it is possible you might taint the baits with traces of the barrier granules. The ants could be repelled by the smell of the barrier granules and not feed on the bait. The chemicals in granular barrier treatments need to be wetted to become active. This helps the binding process needed for the chemicals to work.

It is easy to confuse granular barriers with granular baits, so it is important to read the label carefully. Many granular barriers contain synthetic pyrethroids. The active ingredient list will usually contain one or more chemicals with names ending in “- thrin”, like “bifenthrin”, “cyfluthrin”, etc. Granular barriers also need to be watered before they are activated, while water often inactivates baits.

Never apply a barrier treatment at the same time as bait, because the ants carrying the baits back to the nest will be killed before they have a chance to share it with the colony. Always apply the barrier treatment a few days after you have applied the bait.

Examples of barrier products include Talstar® PL, Ortho® Home Defense, Spectracide® Bug Stop® Home Barrier, Bifen IT.

Contacts sprays are insecticides often sold in pressurized aerosol cans. Most insecticidal sprays are general insecticides which will kill other insects as well as ants. It works at the point of contact with no residual effect, killing only the insects that you see and spray. As a result, it is not very useful for controlling Little Fire Ants, except for instances where you wish to remove individual ants from a particular location for a short period of time.

There is a wide variety of organic and conventional products available in concentrates and ready-to-use formulations. Some may be used on food plants, though they are more effective as spot treatments or for small areas. When choosing an insecticidal spray, read the label carefully to make sure it is right for your situation and to know how to properly use the product for effective pest control.

Examples of contact sprays include Orange Guard®, Sevin® Ready-To-Use Bug Killer, Defender™ Pyrethrum Insect Spray, Spectracide® Malathion Insect Spray.