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In our Ants of Arizona blog series, we’ve been talking about some of the most common types of ants you’ll find in the state of Arizona. We’ve talked about the Carpenter and Harvester ants, and in this entry we’d like to talk all about the ant that may have the fanciest name of them all – Monomorium pharaonis (Linnaeus), or the Pharaoh ant.

But why are they called Pharaoh ants? One theory is that these ants were mistaken as one of the plagues that hit ancient Egypt. They certainly are one of the most difficult household ants to control!

WHAT DO THEY LOOK LIKE?

Pharaoh ants are about 0.05 to 0.07 inches, or 1.5mm to 2mm long. Like all insects, they have 6 legs, and 2 antennae. They are yellowish, light brown, or red in color and typically have a darker-colored abdomen. If seen up close, these ants would appear slightly transparent.

Pharaoh ant workers have non-functional stingers that they use to generate pheromones. Males are slightly larger at about 0.11 inches or 3mm and are winged but they do not fly. Queens are dark red in color, and are larger at about 0.14 to 0.19 inches or 3.6mm to 5mm long.

WHERE CAN I FIND THEM?

A Pharaoh ant colony consists of multiple queens, males, workers, and their young – eggs, larvae, pre-pupae, and pupae. Because they have multiple queens, a single colony can grow very large to as many as 300,000 ants.

Outside, Pharaoh ants like to nest in dark or shaded areas such as under piles of organic debris. Inside homes, they like to nest in warm, humid areas close to food sources. Not only are they able to nest under baseboards, behind wall voids, under floors and such places like most pesky ants do, but they may also nest in furniture, light fixtures, folds of clothing, and even between sheets of paper.

If a colony is disturbed, these ants will often disperse to establish other colonies in the home or surrounding area.

WHAT DO THEY EAT?

Pharaoh ants are omnivores and will consume almost any type of food. Their diet includes nectar, seeds, nuts, sweets, meat, greasy foods, or other insects. While a Pharaoh ant colony may nest indoors, they have been observed to forage close to windows, which may indicate a preference for outdoor foraging.

In a lot of other ant colonies, queens may essentially be waited on hand and foot – but with Pharaoh ant queens, they may “ask” for food from a returning scout that has brought food, and the scout may refuse. This scenario happens when food is scarce, and the scout prioritizes its own survival. I guess being a queen isn’t that special when there are a lot of other queens around.

ARE THEY DANGEROUS?

Pharaoh ants have a non-functional stinger. They’re capable of biting, but this presents no danger except in cases of very large infestations and a person suffers numerous, consecutive bites.

The bigger danger is that these ants may also carry and transmit a number of diseases including salmonella, staphylococcus, and clostridium. They are known to infest hospitals and transmit over a dozen pathogens.

They’re able to nest virtually anywhere inside the house like light fixtures, sockets, insulation – and may wreak havoc inside your house (especially since they will have multiple nesting sites). When they manage to build large nests in indoor structures, they may cause structural damage too.

HOW DO YOU GET RID OF THEM?

Pharaoh ants are one of the most difficult pests to control. They tend to create multiple colonies in one area, and when a single colony is disturbed those ants scatter and create new, smaller colonies that will grow large again very quickly (they can populate a large office block in as little as six months). This is called budding, and is a major nuisance even for pest control professionals.

They may prefer to nest near food and water sources like kitchens and bathrooms, but are also able to travel long distances to forage so their nest may not be nearby. They have been known to use electrical wirings behind walls as bridges to travel so their nests may be difficult to locate.

Insecticide sprays or dust only kills the ants directly affected and not their nests. Any sprays or dusts on the nest would cause the ants to disperse and scatter. Because they have multiple nests that are hard to locate – and because of ant budding – ant bait would be the most effective means to control their population if you’re doing your own pest control.

Be sure to use slow-acting bait, and remove all other food sources to maximize the number of foragers carrying the poisoned bait back to their nests. Use a protein, fat, grease, sugar, or carbohydrate based ant bait. Depending on the nutritional needs of the colony, you may need to change what the ant bait is based on if they’re not being baited by it.

Having an ant problem, especially a Pharaoh ant problem, is a huge headache. If they’ve infested your property, don’t hesitate to reach out to a professional pest control company for assistance.

Check out other types of ants in Arizona here, and our other blog entries on ant topics under our Ant Archives.