The Ghost Ant (Tapinoma melanocephalum) is extremely small, 1.3 to 1.5 mm long and monomorphic (one-sized). They have 12-segmented antennae with the segments gradually thickening towards the tip. The head and thorax are deep dark brown with opaque or milky white gaster and legs. The thorax is spineless, and the gaster (swollen part of abdomen) has a slit-like anal opening which is hairless. Stingers are absent. Their small size, combined with the pale color, make ghost ant workers hard to see. In fact, the ghost ant may not look ant-like on casual inspection. This species runs in quick, erratic movements when disturbed, but sometimes can be found trailing, where movement is more slow and deliberate. On close inspection some trailing workers can be seen carrying brood (larvae and pupae). Workers may emit acrid (coconut-like) odor when crushed. This pungent odor is where the ants gain the name "Corspe Ant" in Malaysia.

The ghost ant is highly adaptable in its nesting habits. It nests readily outdoors or indoors. Colonies may be moderate to large in size containing numerous reproducing females (polygyny). Generally, the colonies occupy local sites that are too small or unstable to support. These sites include tufts of dead but temporarily moist grass, plant stems, and cavities beneath detritus in open, rapidly changing habitats. Indoors, the ant colonizes wall void or spaces between cabinetry and baseboards, and thus is a common indoor pest species.

Multiple queens may be spread out in multiple subcolonies. New colonies are probably formed by budding. This occurs when one or more reproductive females, accompanied by several workers and possibly some brood (larvae and pupae) leave an established colony for a new nesting site.
Workers have the habit of running rapidly and erratically when disturbed. They are fond of honeydew and tend honeydew-excreting insects. They also feed on both dead and live insects.