Birdhouse Maintenance

I clean out and repair my nest boxes each fall so they're ready for birds to use as winter shelters. However, some people say I should postpone birdhouse maintenance until spring. When is the best time?

—Elliot Barnes, Groton, Connecticut

George: If you plan to leave the houses up all winter, then it's best to clean them in spring, when you can remove insects and old nesting materials from both birds and mice. Mice tend to use birdhouses in winter and supplement the birds' nesting materials with their own. Birds also welcome the old nesting materials, as they may roost in the houses on cold winter nights.