Vary in size within one nest, from 1/16 to 1/5 inch long. Fire Ants are dark reddish brown in color on the head and body, with a darker abdomen. Mounds can be more than 15 inches high, 15 inches in diameter and up to 5 feet deep. When disturbed they are aggressive, especially near the nest. Cause painful stings that raise a small welt.
Tawny Crazy Ants
Paratrechina pubens is part of a group of ants referred to as “crazy ants” due to their quick and erratic movements. The Tawny crazy ant is a medium-small (2.6 to 3 mm long), monomorphic, golden-brown to reddish-brown ant. The body surface is smooth and glossy, and covered with dense pubescence (hairs). After feeding, the ant’s gaster (rear portion of the abdomen) will appear to be striped due to stretching of the light-colored membrane connecting segments of the gaster. Antennae have 12 segments with no club. The antennal scape is nearly twice the width of the head. This ant has one petiolar segment and does not sting.
Black Crazy Ants
Crazy Ants are black and range in size from 2.3 to 3mm. While they do have a thinner body, longer legs and longer antennae than most ants, they can be easily confused with other ants establishes in New Zealand. What makes crazy ants distinctive is their erratic, rapid movements especially when disturbed. They do not always follow distinctive trails as other ants do.
Pharaoh workers are very small (about 1/16-inch long), light yellow to reddish brown in color with the abdomen (hind portion of body) somewhat darker. There is no stinger. The petiole (narrow waist between the thorax and abdomen) has two nodes and the thorax has no spines. Eyes are well developed. The antennal segments end in a distinct club with three progressively longer segments. This is in contrast to the thief ant’s two-segmented club.