Ants are the most commonly encountered insects within and around homes, and some ant species are major pests that are capable of establishing multiple indoor nests within inaccessible locations, such as wall voids, ceiling voids, and tight attic spaces. During the summer season, worker ants leave their colony nesting sites and enter homes in order to locate food sources or to escape harsh climatic conditions like drought, excessive heat, heavy rainstorms, and/or flash flooding.

As everyone knows from experience, seeing one or a few ants crawling about indoors does not mean that an infestation has been established. A small number of foraging ants are often lured into homes by the odor of food, but if they cannot access an indoor food source, they will usually leave to forage elsewhere. However, if foraging ants do locate a food source within a home, they will emit an odorous trail pheromone to direct additional workers to the food source.

Ants have a remarkably acute sense of smell and an unusually sophisticated ability to discern between many different food odors. In fact, a recently published study from Vanderbilt University revealed that ants have four to five times more olfactory receptors than most insect pests. In addition to smell, the olfactory center of an ant’s nervous system also processes taste, which explains why ants are able to differentiate between a high number of different food odors. Another study found that being exposed to a food odor just once is enough for ants to remember that food odor for the rest of their lives. Also, their ability to retain these odor memories does not diminish as new odor memories are retained.

Pest management professionals control ant pests within homes by using their incredible sense of smell against them, as baits have displaced insecticides as the most effective method of ant control solely because bait products mix poison with food odors that ants cannot resist. While experts agree that indoor food odors lure ant pests into homes, at least one study suggests that disagreeable weather is the primary factor that motivates ant pests to invade homes. However, this particular study focused only on the Argentine ant, which is an invasive pest that requires unique conditions in order to survive in the US, and therefore, this species is not the best representative of native ants in the US.

Have you ever contacted a pest control professional over an ant infestation within your home?