It's obvious to me (though the photo may not show it) that I'm dealing with little brown ants that are either eating the wood of a stair rail or chewing out the insides and removing it so that they can build a nest of some sort inside. I've had some experience with big black carpenter ants and these brown ants are much smaller than they are. Any help on what kind of critter these munchers are would be appreciated.
I do not believe that these ants are responsible for the wood chips seen in your photo. They do not look like carpenter ants (see http://tinyurl.com/nw69p6 for images of Camponotus nearcticus, the smallest carpenter ant likely to be found in your area), and the size of the wood chips seem out of proportion to these ants' jaws. I suspect that these ants simply are foraging in this material that was excavated by a larger wood-boring insect, but I remain open to other explanations.
Thanks, suunto. We've ripped out some damaged wood which will be replaced. We're also initiating ant control measures in that area. They just look like garden variety little brown ants, so it may just be that they're probably foraging as you said.
