CARPENTER ANT (Camponotus species) Carpenter ants are the most important structural insect pest in many areas of the Pacific Northwest (PNW) because of their habit of constructing nests inside dwellings. Large black ants—often carpenter ants—may frequently be found throughout a house, both inside and out, as well as in surrounding areas. Color is not a reliable identifying characteristic: in the PNW there are several species of carpenter ants that vary from black, to red and black, to a light brown. Carpenter ants vary in size within each species. The most common carpenter ant infesting structures is Camponotus modoc, a black ant with red-brown legs. Carpenter ants commonly nest in standing trees (living or dead), stumps, logs, or on the forest floor. Worker ants from a large “parent” colony, found outside, will frequently move into a dwelling as a “satellite” colony. Workers, often in the thousands, appear in two different size classes: majors and minors. Major workers are the soldiers of the nest, while minor workers mostly expand the nest and collect food. Communication and travel between the colonies are maintained, and the satellite colony may contain larvae, pupae, and winged reproductives. Only parent colonies contain the functional queen, eggs, and early instar larvae. Each spring, carpenter ant nests release large numbers of winged queens. Do not be too alarmed by this phenomenon; most of the queens die before they can start new nests. The queens mate with winged males and quickly shed their wings; thus, you rarely see ants with wings. Carpenter ants do not eat wood, they only nest in it. They eat protein (dead insects) and sweets, especially aphid honeydew, collected from outdoors. Because carpenter ants can build nests in sound, dry wood as well as in wall voids, crawl spaces, and within foam and other insulation, they are capable of causing structural damage and must be taken seriously. There are several ways to detect a carpenter ant nest. You may find sawdust piles near ant entryways. The sawdust is kicked out as digging proceeds. You may observe ants trailing into or out of the dwelling, perhaps through a crack or under the siding (this, by itself, does not locate the nest, it only indicates the presence of one or more nests somewhere inside). You also may hear scraping sounds made by worker ants as they enlarge the nest inside a wall (the house must be very quiet). Finally, nests often are uncovered during remodeling/construction. In early spring, before aphids and other food is abundant, workers may forage indoors, often in kitchens. Common but overlooked passageways into a house are routing holes for telephone, TV, and electrical cables, especially if the cables pass near trees that harbor aphids. Management Control of carpenter ants is best left to competent pest management professionals. They have the experience and the tools necessary to locate nests and apply pesticide products effectively and safely. Drilling wall voids, applying materials inside, underneath and in attic spaces may not be necessary to control carpenter ants, as exterior perimeter treatment with non-repellent materials will control them. If performed during the high foraging season, pesticide is transferred among ants, ultimately eliminating the nest in the structure. When carpenter ants are seen inside during winter, it is best to vacuum them up and wait until the spring foraging season to initiate treatments. - - - - - Thank you for your inquiry. 

Upon further review of the accompanying photo and in consultation with expert analysis, it has been determined that the insect was in fact a type of Mason Bee called a Resin Bee that nests in wood structures in rounded holes. 


The way the megachilid female builds her nest depends on the species. Unlike many other solitary bees that dig nesting tunnels underground, megachilid bees find existing cavities in wood, plant stems, or human-made structures, such as walls or pipes, Some like close neighbors and feel right at home in human constructed nests, like this orchard bee nest or leafcutting bee nest . Many megachilids are opportunists that may also use natural holes, such as this Megachile mendica female provisioning her nest in a dead maple snag . In contrast to megachilids, most bees, like this Stenotritus pubescens, collect pollen on their legs. Some also build their own nests above ground. The female builds the cell walls of the nest using materials found in the environment. Depending on the species, she may use dirt, pebbles, leaves, petals, or resin. This practice is different from other families of bees that secrete their own substances to build their cells. The female megachilid lays a single egg in its own cell. Inside each cell, she adds a loaf of pollen and nectar collected from flowers to feed the larva.   

These bees are docile and it may be wise to clean out the single hole and plug it.  There are presticides available to treat flying insects such as powders and spays.  It is wise to begin with the least invasive treatment.  Remain vigilent for any similar occurances.