I am unfamiliar with the brand "Extinguish Plus" but all effective fire ant baits use a carrier, like fat impregnated cornstarch, grits, cornmeal, or another similar food stuff as an attractant or bait to ensure that an effective insecticide makes it into the nest.
I know that anyone who has ever been bitten by fire ants won't believe this but adult fire ants are incapable of chewing or biting heir food. The adult ants depend on predigested liquid food that is regurgitated by the fire ant larva. Since a fire ant colony can be so deep underground and so wide spread the only thing that will kill them is a poison that kills off the ants' food at its source.
When the ants feed the poisoned food to their young, the larva dies along with the many queen ants in each colony. Without food and with no young young ants to produce more food the whole anthill dies. If you understood the life cycle of either fire ants or else farming practices then you would understand that cutting hay in a field infested with fire ants will disrupt their foraging activities. I bet that the instructions also advise against disturbing the ant hills when you apply the bait. It is because you are rendering the ant bait ineffectiveness by disturbing the mound.
Most fire ant baits have Permeation as the active ingredient. There is almost no likely hood that this insecticide will harm your chickens and even if you bathed your chickens in the stuff there is no withdrawal periods for the chickens' eggs or even for your chickens' "fingers" that is if you tried to gnaw on them. There is a cream for use on new born humans that has 2,000% more of this insecticide in it than "Extinguish Plus" likely has. It is intended for the control of scabies mites.
When you watch this rake winrowing hay then maybe you can understand how much it disturbs fire ants feeding activities to cut and bale hay.
Edited by chickengeorgeto - 11/13/15 at 8:08pm