(Length: 1/8″ – 1/4″) Usually a reddish brown color, fire ants live in colonies of up to 200,000 individuals. Their mounds can be two feet high and three feet across with as many as 50 colonies per acre. The red imported fire ant causes damage difficult to measure in dollars. It’s painful, burning sting results in pustules that take up to 10 days to heal. Some people are extremely allergic to the sting, needing fast medical attention to deal with the toxin.