The sizes of workers, ranging from 1/8-inch to almost 3/8-inch in length. The red imported fire ant was brought into this country during the 1920s and has spread to cover most of the UK. These ants nest in the soil and construct large mounds that are easily seen in lawns and farms. A single lawn may contain a dozen or more mounds. This ant will also locate nests within landscape mulch and beneath items on the ground. Fire ants may construct mounds next to the foundation and enter homes through holes or other exterior cracks.