Carpenter ants carve wood condos but refuse to eat the walls
Camponotus is the ant world's richest genus, with more than 1,500 described species on every continent but Antarctica. Despite the name, only a few of them actually nest in wood, and those that do chew out galleries without eating a crumb, dumping sawdust-like debris outside instead of digesting it like termites.
The wood-nesting minority, mostly in the subgenera Camponotus and Myrmentoma, favour dead, damp timber, carving passages along the grain. In houses they target the wettest spots, around windows, under roof eaves, and in decks and porches, and they rank as a major cause of structural damage. In forests the same digging helps break down dead wood, and colonies sometimes hollow out living trees.
These are big ants. Workers run about 4 to 7 mm in small species and 7 to 13 mm in large ones, queens 9 to 20 mm and males 5 to 13 mm. A key identification mark is the gap between the antenna bases and the front edge of the head, at least as wide as the antenna's first segment, and the thorax usually forms one smooth curve in profile.
Diet mixes scavenging and farming. Mostly foraging at night, often alone, workers find dead insects, drain their body fluids and leave the empty shell, sometimes hauling the head home to empty it too. They guard aphids from predators and stroke them with their antennae to collect sugary honeydew, raising the aphids' survival, and they also take plant nectar and share liquid food mouth to mouth. Underground tunnels may run to aphid colonies, and a central parent nest is often ringed by smaller satellites. In northern Arizona unusually large colonies have been seen bleeding Chinese elms for sap.
Colobopsis, which includes the so-called exploding ants, was once filed under Camponotus, but a 2015 genomic study placed it as sister to the rest of the tribe, and it has stood as its own genus since 2016.
Source: Carpenter ant
