A force to be reckoned with . . .

Ants are some of the most successful insects on the planet. Ants may be found from the hottest desert climates well into the cold sub-arctic. They are far more successful in the temperate regions of the earth. It just happens that is where we like to live, too!


Because ants are so good at finding food and shelter, it isn’t surprising that they are a major pest problem in our homes and other buildings. Aside from being general pests and an aggravation, some species of ants are destructive to our homes and our crops. Some species are actually dangerous to people and our animals. The imported fire ant is responsible for the deaths of people and livestock.


Here in the central San Joaquin Valley we have just over a half dozen species of ants that may be a problem to homeowners and agriculture. We’ll take a brief look at each. For an accurate identification of ants that are troubling you, please call for an appointment, and we’ll have one of our technicians stop by and take a look.



Argentine Ants

Iridomyrmex humilis

The argentine ant is probably the most common ant problem you will find in an urban setting. They were introduced into this country from South America many years ago and have become very well established. As we change the environment by replacing the arid land with houses and landscaped yards, we create just the environment they like. As the areas around our homes become more suitable for them and less suitable for the native ants, the Argentines will actually take over and run off the native species.

Argentine Ant

These little ants (approx. 1/8”) build huge colonies that may forage over a very large area. They are very cooperative with neighboring Argentine ant colonies and each colony may contain multiple queens. You may see these ants trailing in huge numbers along the edge of a sidewalk or up the trunk of a tree. Inside the home they may show up in the kitchen, laundry or bathrooms (or virtually anywhere else, for that matter).


Sometimes trying to treat for these ants only seems to make the problem worse. That is because they have extremely mobile colonies. If the original colony site is disturbed (by spraying insecticides, watering, etc.) they will readily pick up their larvae and move the colony to another location.


Improper pesticide applications can actually fracture or splinter a colony. Since they have multiple queens and are so mobile, it isn’t uncommon for one queen to go one way with some workers while another moves to another area. Thus, what was once a single colony has now become several colonies!



California Harvester Ant

Pogonomyrmex californicus

This California native can be found in dry areas such as pastures, crop fields, parking lots, etc. Their distinctive mound can be easily recognized. The ants tend to keep the area around the nest opening clear of debris. The nest mound will often have a ring of seeds, twigs, etc. a foot or so away from the opening itself.
California Harvester Ant

Look closely at the joint between the abdomen and the thorax and you can see that this ant has two distinct nodes (or joints). This is a clear sign that these ants can bite or sting. In fact, the California Harvester Ant is extremely aggressive defending its nest. Disturb them at your own peril.



Odorous House Ant

Tapinoma sessile

The Odorous House Ant gets its name from the “rotten coconut” smell that it gives off when crushed. They do not pose a significant health risk, but they can contaminate foods and cooking surfaces with their presence. They feed on sweets and are especially attracted to fruits such as melons. Their nests may be found in cracks in the pavement or in wall cavities, under roofing shingles, or other protected areas.


Odorous House Ant


Fire Ants

Solenopsis sp.

In central California we have several species of fire ants. The most common is the native California (or Southern) Fire Ant. The Red Imported Fire Ant has been introduced in recent years. These ants are gaining a foothold in our area and will become an increasingly important pest problem as time passes and they become better established.



California Fire Ant
aka Southern Fire Ant

Solenopsis xyloni

If you have moved into a new home in a newly developed area you may have encountered these aggressive ants. They are a native ant to the San Joaquin Valley. Their nests may be found in open, California Fire Antarid areas or in orchards or vineyards. When we build housing developments in these areas we often place our new homes directly in the foraging areas of these ants.


The California Fire Ant thrives in dry, arid environments and is well suited to our native climate. As we urbanize the Valley and introduce irrigated landscaping we modify the environment around our homes. These new “micro-climates” invite infestations of imported Argentine ants. The aggressive little Argentine ants will destroy the native fire ant colonies and ultimately replace them. In a way, this is good for us, because the Argentine ants don’t bite or sting. However, Argentine ants can be much more difficult to eradicate once they are established. The California Fire Ant can still be found throughout the Valley and foothills where the climate and landscapes more closely resemble the way they were when nature was in charge.



Red Imported Fire Ant

Solenopsis invicta

Red Imported Fire Ant

The Red Imported Fire ant is capable of inflicting serious bites and stings. They will attack any animal or person that encroaches on their nesting or feeding area. They attack in very large numbers and the accumulated effects of their stings can be deadly. They are responsible for billions of dollars in damage to agriculture and are a serious health risk in the urban settings where they have become established. It is estimated that in the USA alone Red Imported Fire Antnearly 33,000 people seek medical attention annually because of Imported Fire Ant stings.


The Red Imported Fire Ant is such a serious pest that the California Department of Agriculture has established a statewide program designed to Red Imported Fire Antcontain, and hopefully control the spread of these destructive pests. If you suspect an ant mound in your property may be Red Imported Fire Ants it is important that you contact a pest control professional or the California Department of Agriculture for identification. You may call our office for a technician to stop by. You may also call your local County Agricultural Commissioner’s Office. Phone numbers are located on our Helpful Links Page or in the Government Pages of the phone book.



Thief Ant

Solenopsis molesta
Thief Ant

The tiny Thief Ant is rarely associated with the biting and stinging Fire Ants of open fields and playgrounds. However, these little creatures have stingers like their larger cousins. Their name comes from their unique behavior of robbing other ant’s nests. Because they are so small they can often “sneak” into another, larger ant’s nest and steal the eggs and young ant larvae for food. The larger ants can’t seem to detect them or defend against them.


Thief ants will be found in kitchens and other areas where protein rich foods may be present. Because they are so tiny, their infestations are sometimes overlooked by the homeowner.



Pharaoh Ant

Monomorium pharaonis

It is believed that Pharaoh Ants originated in Africa. Because they are so adept at hiding their colonies in concealed areas, they have been relocated all over the temperate regions of the earth. Pharaoh ants are now a pest problem in nearly every state in the U.S.


Pharaoh ants may range from a pale tan to medium brown in color. Their nests often contain multiple queens. These nests can be easily “splintered” or broken into many nests when disturbed. These characteristics make the Pharaoh Ant an extremely difficult pest to control. Control of Pharaoh ants should be left to a trained and properly equipped professional.

Pharaoh Ant


Carpenter Ant

Camponotus sp.

Carpenter ants are widely distributed. Almost every state in the United States has one or more native species. These ants get their name from their habit of building their nesting galleries logs or lumber. Unlike termites and other wood destroying insects, Carpenter AntCarpenter Ants do not actually eat the wood. Instead, they tear the wood with their powerful jaws (mandibles) creating hollowed out areas in which they build their nests. Carpenter Ants can do significant damage if the nesting gallery happens to be in a home or other structure made of wood.


The good news for homeowners in the central San Joaquin Valley is that Carpenter Ant damage to homes is very rare in this area. The Carpenter Ant queen requires a fairly moist, humid environment in which to develop her brood. Our dry, Mediterranean climate Carpenter Antsdiscourages development of Carpenter Ant colonies in our area. However, these insects can present a significant problem to property owners in the nearby foothill and mountain communities such as Bass Lake, Shaver, Huntington, etc.


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