It's hard not to admire the work of carpenter bees: the perfect roundness of the holes they bore, the steady stream of sawdust day after day. Except these specialized bees (and less tidy ants) are more excavators than carpenters, and can bore through girders, fascias and any other wooden parts of a building.
Male carpenter bees are territorial, and may lazily circle anyone near the nest. But males don't have stingers; they're harmless. Females will sting, but typically only if touched, as they're devoted to digging, and often will continue boring (about one inch in a week) as you stand and watch only a few feet away. Carpenter ants, on the other hand, will bite defensively, but usually flee instead.
Neither insect actually eats wood. The bees feed on pollen and nectar, and pollinate flowers and trees. They're good for your yard, but in numbers, can turn fascias into Swiss cheese. The ants feed mainly on insects outside, and on meats or anything sugary inside. All the digging is their version of construction: building a sheltered network of tunnels, called galleries, inside the wood of your house.
The Ohio State University Extension characterizes carpenter bees as "nuisance pests" that cause more cosmetic than structural damage. But successive generations can resettle and enlarge existing tunnels, undermining the strength of a board. And though the entry holes are neat, the fecal staining below the holes is not. And sometimes the bee's excavation is off center, causing the tunnels to break through the surface. Get close enough to one of the holes, and you'll likely hear the buzzing, or even feel the vibration through the wood surface. So do woodpeckers. They know there's a meal inside, and can add to the damage by pounding their way through to the tunnels.
Carpenter ants are more invasive, and will dig in close to food and moisture sources in kitchens, baths, and other living areas. Most forage sunset to midnight during spring and summer, which conjures that creepy scene when you flip on the lights to raid the fridge at night, and watch them scatter. The Ohio State University Extension says if you spot 20 or more indoors, in the daytime near one location, there may be a well-established colony in the home. But if you see only a few, they may be foraging from a nest outside. Workers travel up to 100 yards from an outside nest in search of food.
Many extension service Web sites offer detailed descriptions. The short take? Carpenter bees are like bumblebees: big, round, and buzzing. But bumblebees have dense yellow hairs on the abdomen and large pollen baskets on the hind legs -- and they nest in the ground, while carpenter bees nest in wood.
Carpenter ants are usually larger than other ants, often 3/8 - to 1/2-inch long, and have one node, or segment, at the waist between the two main parts. If you're finding wood damage and need to distinguish between carpenter ants and termites, here's the comparison. Carpenter ants have dark-colored bodies, narrow waists, elbowed (bent) antennae, and are frequently seen in the open. Termites are light-colored, have no waist constriction, straight antennae and are rarely seen outside their colony.
For carpenter ants, caulk any openings into the house. Utility lines are a favorite highway. Also dry out, or replace wet, decaying wood. The next step, by yourself or after hiring a pro, is to find the nest. The University of Minnesota Extension suggests a stealthy approach: setting bait -- some honey and bits of tuna fish -- then watching between sunset and midnight using a flashlight with a red film over the lens. As ants can't see red, the idea is not to startle them as they lead you straight back to the nest. Piles of sawdust are another giveaway. Professionals typically drill small holes and shoot insecticide dust into the nest area. Boric acid is one do-it-yourself remedy. But the University of Minnesota Extension says "there are no insecticides available to the public that are labeled for this type of application." If the nest is exposed they suggest a liquid or aerosol, ready-to-use ant