Carpenter Ant colonies typically contain 10,000-20,000 workers, but can contain as many as 100,000 with one queen per nest. Nests usually originate in decayed wood and later expand into sound wood. Look for coarse sawdust piles (frass) that will also contain insect body parts and listen for the sound produced as workers chew to remove wood to enlarge the nest. Outside, nests are commonly found in dead or damaged portions of trees, rotting logs and stumps and landscape timbers.
Argentine ant colonies live in moist areas near a food source. Colony numbers fluctuate seasonally, ranging from one hundred to several thousand workers and many queens. Foraging workers follow trails; winged queens can sometimes be found among them. Argentine ants live outdoors in shallow nests in moist areas, including under boards and stones, beneath plants and along sidewalks. Argentine ants will also nest indoors. When outdoor conditions are too wet or too dry, Argentine ants invade buildings by trailing along tree and shrub branches, utility lines and wires.
Odorous House Ants
Odorous house ant colonies may contain up to 100,000 ants with many queens. Super colonies may exist where food, water and brood are exchanged between satellite locations. Indoors, odorous house ants nest in wall voids, especially around hot-water pipes and heaters, and in crevices around sinks and cupboards. Outdoors, nests are often found in soil, usually under objects. Odorous house ants are most likely to enter buildings when colonies become very large and natural food and water sources become scarce and when climate conditions are extreme (drought or flood).
Colonies average 3,000-4,000 ants with several queens. Pavement ants normally nest in soil; however, they occasionally nest indoors in walls, insulation and under floors. Colonies will move near a heat source in winter. Pavement ants often follow pipes through slabs to access buildings. Outdoors, these ants nest in soil under stones, slabs, next to buildings and in pavement cracks. They enter through cracks in slabs, expansion joints and natural openings of buildings. Pavement ants like to travel under the edges of carpet next to the tack strip. To inspect or treat this area, carefully lift the carpet a small section at a time, then press down firmly to replace the carpet. Soil nests may have a characteristic “dirt crater” around the opening. Pavement ants forage up to 30 feet in trails.
Pharaoh ant colonies range in size from several hundred thousand workers and several hundred reproductive females to very small colonies with 100 workers and one or two females. These ants nest almost anywhere, but prefer warm, humid areas near sources of food and water – in wall voids, behind baseboards, in furniture, under floors and between linens. In southern regions, colonies can exist outdoors. Workers range widely from the nest and establish visible trails to food and water sources. Pharaoh ants commonly use electrical and telephone wires, plumbing and other utility lines as trail routes. Outdoors, these ants nest in debris collected on flat roofs, entering and exiting via poorly caulked or defective windows, under flashing and through weep holes.”