Around 400 ant species belonging to the Monomorium genus have been documented. Worker ants from this genus tend to be dark brown to black and relatively small at 1 to 2 mm in length. These ants feed on honeydew in the natural environment, and many are known to invade homes in search of a variety of food sources, particularly sweets. Some Monomorium species maintain long term habitats within human dwellings, but most nest in soil outdoors. However, one species in this genus, Monomorium floricola, is unique for nesting in above ground wood sources, such as live and dead trees, stumps, branches, and even twigs. These ants frequently invade homes in search of food sources, and although they are capable of establishing indoor nests, they are not believed to excavate nesting cavities in structural wood. While this species is one of the most widely distributed of all known ants, they can only be found in the southern areas of the Gulf Coast states within the US.

floricola workers usually invade homes from outside nests located in trees and ornamental vegetation, particularly shrubs. Indoors, workers may establish nests within wall voids where entire colonies are sometimes found in small cracks and crevices. Due to their excessively small size, colonies are easily transported into homes and non-native areas of the US. In addition to the small size of colonies, M. floricola do not spread to new areas via swarming, as most ant species do; instead, M. floricola colonies contain numerous queens that leave active nests in order to establish new colonies elsewhere. This form of colony dispersal is known as “budding,” and this dispersal habit makes infestations difficult to notice. Although rare, these ants can infest attics and upper levels in homes after accessing roofs and siding from tree branches that make contact with the exterior of homes. M. floricola workers prefer to remain in close proximity to kitchens due to their appetite for protein and sugar-rich human food sources.

Have you ever encountered numerous ants in your attic?