Larry go ahead & remove the old nests now if weather permits, as they begin scouting in late January and February. Also you really NEED to move the box higher than 3′ from the ground – this is dangerously low & makes it easy for predators to have a meal (by jumping/climbing the pole). You may have to wait until warmer weather if the ground is frozen. You may get by, but you wouldn’t want anything to get to your bluebird eggs or babies. Look at the top of this page under Bluebird Information-Housing, and about 2 lines down tells about box height.
Also a baffle under the house is a good idea.
