ExtinguishPlus does work, but seems to work best if it's broadcast instead of treating individual mounds. I spread it in my yard earlier in the year with a hand carried rotary spreader--dunno how you'd do a whole pasture tho, since recommeded rate is about 2 lbs/acre. Restrictions apply: TIPS: This product can take 4 to 7 days to see results, however, you should only apply this product if the soil temperature is about 65 degrees, it is not going to rain within 8 hours, and the fire ants are foraging. It is recommended to broadcast the treatment instead of mound treat for best results, and you should apply the product where the ground is in the sun, since this is where fire ants will nest. You can use this product on pastureland, however you must remove all grazing livestock for at least 48 hours after application. Then they can return to the land after 48 hours.