Termites are the most well known insect pests of structural wood within homes, but they are far from being the only pests that damage finished wood sources. For example, many  beetle species excavate nesting galleries within structural lumber, and feed on the cellulose in wood during their larval stage. These beetles are commonly referred to as “wood-boring beetles,” and some of the most common and economically significant wood-boring beetles include old-house borers, powderpost beetles, false powderpost beetles, and deathwatch beetles.

In addition to beetles, several ant species are well known for tunneling through wood for the purpose of nesting, but no ant species is known to consume wood as termites and some beetles do. Almost all wood-damaging ant species belong to the Camponotus genus, which includes well over 1,000 ant species, most of which are not pests. Camponotus ant species that are known pests of homes are commonly referred to as “carpenter ants,” and with the exception of subterranean termites, these ants are the most economically significant pests of structural wood in the US.

A recent nationwide survey of pest control professionals found that carpenter ants are the most commonly controlled ant pests of homes and buildings, and they are the second most commonly controlled wood-damaging pests. The black carpenter ant is the most destructive carpenter ant pest species in the country, but they do not inhabit the westernmost states. In southern California, the western black carpenter (C. modoc) ant is the most common and economically important carpenter ant pest of homes, followed by C. vicinus (no common name). Like most carpenter ant species, the two above named species see workers grow to sizes ranging from ⅕ to ½ of an inch in length, which makes them the largest ant pests of homes in the US.

In most carpenter ant infestation cases, workers forage in homes from outside nests, but if initial carpenter ant invasions are not promptly controlled, workers often go on to establish “satellite nests” within inaccessible indoor areas, most commonly within wall voids. Not long ago, professional entomologists surveyed 30 pest control professionals in the wesern US and western Canada about where carpenter ants most frequently nest within homes. The responses in order of the most to least commonly encountered indoor carpenter ant nesting sites were: wall voids, ceilings voids, behind siding, substructural wood in contact with soil around crawl spaces, by downspouts near tile roofs, under shingles, in hollow doors, in window sills, and in padded ceiling insulation.

Have you ever found carpenter ant workers foraging in your home?

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