In addition to being ubiquitous outdoors, ants are the most abundant insect pests within residential homes and urban buildings. Ants invade and nest within single family homes, apartment complexes, restaurants, office buildings, schools, residential care facilities, and even hospitals. Since the early 1970s, the extremely troublesome Pharaoh ant (Monomorium pharaonis) has repeatedly infested numerous Texas hospitals. Unfortunately, Pharaoh ants are more than just a nuisance, as they are also capable of mechanically transmitting diseases to both humans and animals.
Countless studies have shown that Pharaoh ants carry more than a dozen disease pathogens including strains of Pseudomonas, Salmonella, Staphylococcus, Streptococcus, Klebsiella and Clostridium. Because of this, the US Food and Drug Administration includes the Pharaoh ant on its list of organisms that are capable of transmitting food-borne pathogens. This list is known as the “dirty 22,” and it also includes the four primary cockroach pests in the US, 12 fly species, and two ant species, the other being the thief ant (Solenopsis molesta). Since Pharaoh ants carry several disease pathogens, a hospital may be the worst possible location for these ants to establish an infestation.
In 1982, Pharaoh ants were found infesting areas of more than 60 hospitals throughout Texas, some of which were located in Houston. The filthy ant pests were often found within intravenous tubes, glucose solutions, nursery cribs, and one incident saw three Pharaoh ant workers removed from a surgery patient’s open neck. However, the ants were most frequently found congregating in open wounds, and they were particularly numerous in burn units where several severely injured patients were found covered in Pharaoh ants.
Many pest control professionals agree that the Pharaoh ant is the most difficult ant pest species to control, and there are several reasons for this. First of all, Pharaoh ant colonies house multiple queens, each one of which can readily start an entirely new colony without swarming. In homes, Pharaoh ants establish multiple nests, and sometimes, multiple colonies within wall voids and other inaccessible areas. Treating Pharaoh ant nests with insecticide spray causes them to immediately split into two separate nests, and possibly, two separate colonies. Pharaoh ants workers are also excessively small, and they are known to disperse to all indoor areas where they establish secondary nests in unusual locations, such as televisions, appliances, heating ducts, and electrical outlets. In order to eliminate infestations, all indoor and outdoor nests must be pinpointed and destroyed. Most pest control professionals use insect growth regulators and baiting systems to eliminate Pharaoh ant infestations.
Have you ever encountered Pharaoh ant workers foraging within your home?