Little Black Ants ( Monomorium minimum) mostly forage in the Blue Palo Verde tree or on the ground. They prey on small insects. They carry a sting but are too small to inflict it upon a human.
Red Imported Red Fire Ants (Solenopsis invicta) and Southern Fire Ants (Solenopsis xyloni). The Arizona Department of Agriculture has been successful at keeping the Red Imported Red Fire Ants controled by eradication.
Southern Fire Ant don’t usually cause much harm. unless it becomes very hot or very cold and then they may move indoors.
Both ants will sting, however the Red Imported variety is highly aggressive.
The Maricopa harvester Ant (Pogonomyrmex maricopa) plays a major role in decomposition by dragging dead carcasses of insects underground, thereby enriching soil for plants and crops. It has the most toxic insect venom known. It bites and then repeatedly stings.
Carpenter Ants (Camponotus spp.) They tunnel in the wood of stumps, logs, dead standing trees, the interior dead sections of livings trees, and the wooden portions of buildings. The wood borings, which are coarse and fibrous, are pushed out of the tunnels and may accumulate at the base of inhabited trees. They do not eat the wood, but seriously cause structural damage. They prefer wood that has been damaged by something else, usually water – although carpenter ants will often take over some other kind of damage – such as old termite damage. They do not sting.