Carpenter ants seem to prefer voids for nesting which have these characteristics:
- Close to moisture and food sources
- Safe from predators such as birds and lizards
- Safe from flooding, heat, and other environmental stresses
- Easily accessible (for them, but inaccessible for the Pest Control Manager!)
They will hollow out wood softened by moisture and/or fungi to create nests. This wood can be in tree stumps or dead tree limbs, or in any part of a structure having damaged wood. They will not excavate nesting galleries in sound wood. Bits of debris, called frass, are often ejected from nesting sites. Frass consists of bits of excavated materials and pieces of dead insects, including carpenter ants.
Common exterior nesting sites include: old dry-wood termite galleries and wooden objects that have had previous damage from other organisms including insects or fungi; rotting tree stumps and tree holes or crotches between limbs; under old leaf petioles in palms, especially in and around the inflorescence of coconut palms; under bark, in roots of trees, especially citrus trees; in old wooden fences, sheds, old wooden decks, bamboo poles (even thin or short pieces) or tree supports, debris of almost any kind, coconuts left on the ground, under mulch, inside logs or wooden borders in gardens, railroad ties, old shoes, in voids in ceramic or concrete decorations, walls or support pillars, in expansion joints either not filled in or filled with rubbery materials, under stones, in home exterior coverings, especially wood panels, and so on.
Common interior nesting sites include: wall voids (especially walls that have moisture seepage), under attic insulation and usually near the eaves where they are very difficult to reach, under bath tubs, very common under windows and door frames which have moisture intrusion from rain or sprinklers, around skylights, in boxes or paper bags, in closets which are not often used, under appliances, especially dish washers, in flat roofs (one of the most difficult problems due to lack of adequate access), behind wood panels, in wood furniture, cracks in floors, under bathroom fixtures, and many other places! Carpenter ants are sometimes found in electrical boxes, such as fuse, meter, or timer boxes or appliances. Unusual nest sites have included a computer printer, a radio, and a pay phone. Also check hollow supports of patio screens or voids in patio ceilings.