Odorous House Ants
Description: Odorous house ant workers are brown to black and 1/16 to 1/8-inch long. The best identifying characteristic is the rancid butter smell these ants produce when they are crushed, hence their name. When alarmed, the workers scurry around with their abdomens raised in the air.
Carpenter Ants
Description: The carpenter ant, Camponotus pennsylcanicus, is in the east and C. modoc in the west are the most thoroughly studied species in the U.S. They are among the largest ants found in the U.S., ranging from 1/8 to ½ inch long, the queens are slightly bigger. The workers of an established colony vary in size. They are commonly black, although species are other colors.
Pharaoh Ants
Description: Pharaoh Ants are very small: workers are about 1/16 inch long. They range from yellow to light brown. They can be distinguished from the thief ant because they have a three-segmented club at the end of the antenna. The Pharaoh Ant is so small that the whole colony can exist under a wet mop in a broom closet, or in the light switch box on the wall.
Pavement Ants
Description: Pavement ants are 1/16- 1/8 inch long with a dark body and lighter colored legs. They are easily identified by the narrow, parallel grooves on their heads and thoraxes.
Argentine Ants
Description: The Argentine Ant is a relatively small ant (the workers are about 2.5 mm in length and the queen is about double that size), light brown to dark brown in color and have one node on their pedicel.
Acrobat Ants
Description: Acrobat ants get their name from their habit of raising their abdomen above their head, especially when they are disturbed. When they are viewed from above, the abdomen is heart-shaped. Most species are less than 1/8 in length. Many give off a disgusting odor when disturbed.
Thief Ants
Description: Thief Ants are very tiny ants, workers are never more than 1/16- inch long. Thief ants are yellow to light brown and look much like Pharaoh ants.