Every type of ant bait is a combination of food and an active ingredient. The food makes the bait attractive to the ants. The active ingredient makes the bait toxic to the ants.
Many brands of fire ant baits use an insecticide as the active ingredient. This provides fairly quick control. After an ant eats some of the insecticide bait, it dies. The manufacturers have to try to make the bait weak enough so the workers can get the bait back to the nest before they die. It is important to apply enough bait so that every ant can eat some of it. If some of the ants survive, the problem will quickly re-appear.
Some people have been reluctant to use ant bait, especially outdoors. They were afraid that birds, wildlife, or pets could eat some of the bait and become sick. To keep this from happening, bait manufacturers made a type of fire ant bait that controls the ants without posing a risk to wildlife and pets.
Bait manufacturers made a breakthrough when they came up with ant bait with a different type of active ingredient. The bait manufacturers removed the insecticide from the bait and used an insect growth regulator (IGR) in its place.
Insect growth regulators are designed to decrease or eliminate a hormone in the body of an insect. The advantage for humans and animals is that the hormone only occurs in insects.
Since the hormone does not occur in humans' or animals' bodies, the IGR cannot cause it to decrease. Humans and pets face very little risk from the insect growth regulator because it can have little or no toxic effect on them.
Fire ant bait with insect growth regulator can be applied to pastures where cattle and other livestock will graze. The bait can also be applied to sports fields, parks, and golf courses.
Homeowners who are fighting fire ants may see one difference with bait that contains insect growth regulator. The bait will work very slowly. The reason is that the growth regulator only works on the queen. When the queen eats some of the bait, the growth regulator causes her to produce eggs that cannot hatch. When the queen stops producing eggs, the colony begins to die. As the workers die, there are no new workers to replace them.
The label on the bait package will have directions for the application. The label will specify how much bait should be applied and also when the bait may be re-applied. Always read and follow label directions.