After some excavation, the pair flew away and I have a sneaking suspicion that they decided the snag was not quite appropriate for them, and I have to agree. It was in a poor location and is so rotten it might fall soon. The snag is only about 6 feet tall, too, so no danger to anyone, except the chickadees if they nest in it. You can see the sawdust from the strenuous explorations on this chickadee.