How can I get rid of the...

Female carpenter bees make long tunnels in wood to store pollen and eggs. They like redwood and unpainted deck timber, or painted wood with some holes already started. Carpenter bees drill into the wood and tunnel with the grain. They may spend the winter in these tunnels. Dust the tunnels or inject them with pressurized liquid insecticide. Insert a dusted plug of steel wool or copper gauze in the tunnel; fill the opening with caulk, wood filler, or a wooden dowel. A dusted plug stops new adults that otherwise would emerge through shallow caulking.