IPM for Ants in Schools
Common House-Invading Ant Species
| Species | # of nodes in the pedicel | Description of Workers | Habits | Distribution |
| Argentine ant Linepithema humile (formerly known as: Iridomyrmex humilis) | 1 | light to dark brown; around 3/32 to 1/8 inch (2.2-2.6 mm) | frequent house invader; nests in a wide variety of places outdoors and inside; multiple queens; prefers honeydew from aphids, scales, etc., but is an opportunistic species and will feed on other sweets, protein, and grease | MD, west to IL, TX, AZ, CA, OR, WA, HI |
| Pharaoh ant Monomorium pharaonis | 2 | small, around 1/16 to 1/12 inch (1.5-2.0 mm); yellowish to red; often confused with thief ant, but has 3 segments in the club-like structure at the end of the antennae | nests in any secluded spot; prefers temperatures between 80o and 86o F; frequent house invader; often found around kitchen and bathroom faucets where it obtains water; feeds on sweets but prefers fatty foods, and eats dead insects | throughout U.S. and Canada |
| thief ant Solenopsis molesta |
2 | very small, around 1/16 inch (1.3-1.8 mm); yellowish; often confused with Pharaoh ant, but has 2 segments in the club-like structure at the end of the antennae | often lives in association with other ants as predator of brood; omnivorous but prefers grease or high protein foods over sweets; frequent house invader, may nest indoors in cracks and cupboards | throughout U.S. |
| little black ant
Monomorium minimum |
2 | very small, 1/16 inch (1.5-2.0 mm ); jet black | small craters of fine soil mark nest openings in ground; will also nest in the woodwork or masonry of buildings; omnivorous; occasional house invader | throughout U.S. |
| big-headed
ant
Pheidolespp. |
2 | around 1/16 to 1/8 inch (1.5-2.4 mm); yellowish or light to dark brown; head large in major workers | nests in and around the house; prefers greasy or high protein foods | NY to NE, south to FL & AZ |
| pavement ant
Tetramorium caespitum |
2 | around 1/10 to 1/8 inch (2.5-3 mm); light to dark brown or blackish; head & thorax furrowed by parallel lines | nests under stones & edges of pavement, in winter will nest in houses in crevices adjacent to a heat source; slow-moving; tends aphids for their honeydew; feeds on seeds; insect remains, and greasy materials | common along the Atlantic seaboard and in central CA; sporadic in Midwest |
| odorous house
ant
Tapinoma sessile |
1 | around 1/10 to 1/8 inch (2.4-3.25 mm); brownish to black; foul odor when crushed; darker than Argentine ant | frequent house invader; nests in a wide variety of places outdoors and inside; multiple queens; colonies are more localized than those of the Argentine ant; food habits are similar to the Argentine ant | throughout U.S. |
