Red and Black Ants Identification: 7 Species Compared

The red and black ants described by UC IPM, UMN Extension and DoMyOwn are carpenter ants, acrobat ants, velvety tree ants, fire ants and field ants, and where the red sits on the body separates them quickly.

• Red middle (thorax), black abdomen, brownish-black head: velvety tree ant (UC IPM).
• Amber head and thorax, black abdomen: southern fire ant (UC IPM).
• Reddish all over with a darker brown abdomen: red imported fire ant (UC IPM).
• Large, black with red on the front half: carpenter ant, which UC IPM describes as black or bicolored red and black and UMN Extension as black, or black and red.
• Black and red with a heart-shaped abdomen often held up over the body: acrobat ant (DoMyOwn; Wikipedia).
• Mix of black, brown and red, nesting in soil mounds in the open: field ant (UMN Extension).
• Black with a bright orange-red pattern on top, about 3/4 inch, seen singly in summer: red velvet ant, which is a wasp (Wikipedia).

Then confirm with the waist. Ants have one or two bumps (nodes) in the narrow waist; see ant identification for how to count them.

• Carpenter ant (Camponotus): workers 1/4 to 1/2 inch, one node; nests in tree stumps, firewood, fence posts, hollow doors and window frames (UC IPM); workers 3/16 to 1/2 inch and queens up to 3/4 inch, with an evenly rounded thorax (UMN Extension). It bites (UC IPM) and has no stinger (DoMyOwn). The ferruginous or red carpenter ant, Camponotus chromaiodes, lives in the eastern US (Wikipedia). More in carpenter ant identification.
• Acrobat ant (Crematogaster): about 1/8 inch, two nodes, black and red, with a stinger (DoMyOwn); Terminix gives 1/8 to 1/4 inch and light red to brown or black. The heart-shaped abdomen can be raised over the thorax and head when disturbed (Wikipedia).
• Velvety tree ant: 1/8 to 1/4 inch, brownish-black head, red thorax, velvety black abdomen, one node; an aggressive biter with a very distinct odour when crushed; nests in dead wood such as old limbs, stumps and logs (UC IPM).
• Southern fire ant: 1/8 to 1/4 inch, amber head and thorax, black abdomen, two nodes, stings; nests in small mounds with flattened, irregular craters, in wood or under rocks (UC IPM).
• Red imported fire ant: 1/16 to 1/5 inch, reddish with a dark brown abdomen, two nodes, an aggressive stinging ant; nests in mounds with multiple openings in soil or lawns (UC IPM). See fire ant stings.
• Field ant (Formica): 1/8 to 1/4 inch, black, brown, red or a combination, one node, with distinct simple eyes (ocelli) on the head; nests in soil in exposed areas, sometimes in mounds up to 10 inches, and is less likely to forage indoors than carpenter ants (UMN Extension).
• Pharaoh ant: very small, about 1/16 inch (UMN Extension), yellow-reddish with black shading at the rear of the abdomen, two nodes (DoMyOwn; UC IPM). It lives strictly indoors in cracks and voids (UMN Extension). Its colour is more yellow than red.

A black insect with a bright orange-red pattern on its back, about 0.75 inch (1.9 cm) long and seen in summer, may well be a red velvet ant, also called a cow killer. It is a parasitoid wasp, not an ant: the females are wingless, and the males have dark wings. It is the largest velvet ant in the eastern United States, ranging from Connecticut to Kansas and south to Florida and Texas (Wikipedia).

Its sting ranks 3 out of 4 on the Schmidt sting pain index (Wikipedia). Do not pick it up. If someone is stung and has trouble breathing, swelling of the face or throat, or feels faint, call emergency services.

Identify the ant first, then use baits and treat the nest; spraying the ants you see rarely solves the problem.

• Baits first. UC IPM calls baits a key tool and the only type of insecticide recommended in most situations. Worker ants carry bait back to the colony. UC IPM says it can take 5 to 10 days to see fewer ants, and UMN Extension says baits may take several weeks to several months to eliminate a colony.
• Find the nest. UMN Extension's advice is to follow the ants and watch where they go. For carpenter ants the nest is often in damp or rotting wood, and replacing damaged wood is part of the fix (UMN Extension).
• Why sprays disappoint. Only a small share of a colony is outside the nest at any time, so killing foragers has little effect (UMN Extension), and spraying around the foundation kills only foraging ants (UC IPM).
• Skip the kitchen remedies. UMN Extension lists spearmint gum, red pepper, orange peels, cinnamon, herbs, lavender and other essential oils as not effective.
• Fire ants. In California, UC IPM asks people to report a suspected fire ant infestation to the county agricultural commissioner.
• Call a professional if ants keep coming back after you have tried these steps (UMN Extension).

• Photograph the ant from the side, so the waist nodes and the curve of the thorax show.
• Put a ruler or coin next to it; size alone separates a 1/2-inch carpenter ant from a 1/16-inch pharaoh ant.
• Note where it was: a trail to the kitchen, a soil mound, a hollow door or dead branch.

InsectLens identifies ants from a photo.

Research and drafting for this page used AI assistance, and every fact was checked line by line against the sources listed below. Each number, date and quotation names the organisation it came from. The page does not replace a clinician, a veterinarian or a professional identification.