These ants get their common name from the exceptionally large head of the major workers in relation to their body size. Various species are found throughout the United states including Hawaii. A few species serve as intermediate hosts of tapeworms which infect turkeys, chickens, and domestic fowl.
Most form small (200- to 300-member) colonies, but colonies of some species contain thousands of ants and multiple queens. Big-headed ants enter buildings occasionally, preferring to nest in protected soil (such as under stones, leaf litter, mulch, patio blocks, slabs, firewood and landscape timbers). Some nest in open areas where they make small mounds, or in crawl spaces in termite-damaged wood.