The black carpenter ant, is the largest and most common house-infesting carpenter ant in Missouri. Individual workers range in size from 1/4 inch to 5/8 inch in length. This species is generally totally black.
Carpenter ants may become household pests by foraging for food indoors. The diet of carpenter ants includes living and dead insects, meat, fats and sweets of all kinds, including honeydew from aphids and nectar from plants. Foraging workers collect all the food for the colony and may travel up to 100 yards from the nest in search of food.
Carpenter ants normally construct their nests in hollow trees, logs, posts and landscaping timbers. They prefer to nest in wood that is moist and rotting or that has been hollowed out by decay or by other wood-destroying organisms. Carpenter ants remove wood in the form of a coarse sawdust-like material, which they push from the nest. This often results in a cone-shaped pile accumulating just below the nest entrance hole. This pile may include other debris from the nest, including bits of soil, dead ants, insect parts and other food remnants.
The greatest concern with carpenter ants is that they will establish satellite nests in structural wood. This can cause serious damage. They will establish these nests in areas such as the roof trim, siding, rafters, joists, sheathing, decks, porches, steps, sills, subflooring, doors and window frames. They may also establish nests inside hollow areas, like hollow doors or small voids produced during construction. Most often, they establish nests in areas of the structure where the wood is moist or has been damaged by moisture. They can also move from decaying portions of the wood into sound lumber in the process of enlarging the nest.
Leaking roofs, gutters, water pipes or other sources of moisture coming into contact with structural wood create conditions attractive to carpenter ants. Eliminating these conditions greatly reduces your risk. Openings in living trees and branches of living trees that touch the structure also increase your risk of carpenter ants because they use these branches as bridges to gain access to the building. Close openings in trees and keep tree branches pruned to reduce ant traffic onto the structure.
Stacks of firewood or other lumber outdoors are attractive nesting sites. Store the wood off the ground and away from the house. It is better to keep only the amount of firewood that you would use during one heating season because the longer wood is left undisturbed, the more likely it is that carpenter ants will occupy it. Spraying firewood to protect it is not recommended.