There are several species of black ants that bite. Under most circumstances, an ant bite may hurt but will not be dangerous. There might be a small welt and some itching, but nothing worth seeing a doctor about. Fire ants, however, are a different story and may require medical treatment since some people are allergic to their venom. If you think all fire ants are red, you're mistaken. Black fire ants may not be as common, but their venom is as painful as that of red fire ants.
Acrobat ants (Crematogaster spp.) are about 1/16 to 1/8 inch long and may be black to light brown in color. Their name comes from their ability to raise their abdomens over their heads. Worker acrobat ants have been known to bite aggressively and release a repulsive odor when they are disturbed. Nests are usually outdoors under stones, in the soil or in old trees. They can occasionally be found nesting indoors, where you'll want to get rid of them.
Carpenter ants (Camponotus spp.) are about 1/4 to 1/2 inch long and can be black, red, brown or yellow. They are the largest black ant found in homes and are often mistaken for termites. Although carpenter ants will carve out tunnels in wood like termites, their tunnels are smooth and done only to create pathways to the nest. They have strong jaws and will bite if handled, at which time they may inject a formic acid into the wound. Nests are often found in rotten wood, either outdoors or indoors.
Pavement ants (Tetramorium caespitum) are about 1/8 inch long with a brown or black body. Although rarely aggressive, they have the ability to both sting and bite. They are called pavement ants because they are often found alongside sidewalks, cement slabs and building foundations. They may also be found under stones, wood and boards. Finding the nest and treating it with an insecticidal dust is usually the only method for control, since baiting is rarely effective for this ant species.
Black Imported Fire Ants
The black imported fire ant (Solenopsis richteri) is nearly identical to the red imported fire ant (Solenopsis invicta). Both are small ants, about 1/8 inch long, but the black imported fire ant is dark brown or black in color as opposed to reddish brown. Black varieties are also less aggressive, which may be why they are not as well known. Beyond that, the two ants are nearly identical in characteristics. Fire ants attack by biting their prey and injecting venom with a stinger. The venom causes an intense burning sensation and creates a white pustule at the bite site.