Fire ant bait materials have a variety of active ingredients with varying toxicity levels. Because such a small amount of active ingredient is in the bait, humans or animals would have to eat a huge amount before getting sick or dying.
The LD50 standard refers to the lethal dose needed to kill 50 percent of the test animal population. For example, to exceed the oral LD50 standard, a 50-pound dog would have to eat 9 pounds of Amdro (hydramethylnon) fire ant bait.
Find more information about fire ants in eXtension's Imported Fire Ant Resource Area.