Carpenter bees can be destructive by burrowing into wood and leaving tiny holes everywhere. They are not eating the wood but merely making a nesting area. The problem is that once you start getting them, more carpenter bees come, and you end up with a lot of small holes in your wood. They are not aggressive insects at all, but are very persistent, so sometimes killing them is your only option.
Remove the carpenter bees from the wood by using the smallest nozzle on your vacuum cleaner. Place it over the holes and vacuum up the carpenter bees. You can even vacuum them out of the air if the vacuum is strong enough.
Stop the carpenter bees by blocking up their holes. Use wood putty or caulk to fill in the hole that the bees have made. This will either kill them if they are still in the hole or discourage them from coming back. You can also stain or seal the wood to deter the carpenter bees. You can also add protection such as aluminum siding to the exposed wood.
Any type of insecticide you have at your home should work to kill the carpenter bees. If you do not have any insecticide at home, then use WD-40 because carpenter bees are deathly allergic to this and will die.