You can help birds survive the coldest days of winter, by providing a winter roost box. You'll need wood...I like roughsawn cedar...dowel rod, glue, nails, and wood screws. Following the instructions, carefully measure and cut out the six pieces. Drill a 12inch diameter hole in the front piece of the house, near the bottom. Use the rough side of the wood for the inside of the box or drill four holes into, but not through, the wood...and insert perches. Since heat rises, the entrance hole at the bottom means the box will stay warm. And when spring finally comes, rotate the front to convert it into a bluebird house!

http://mdc.mo.gov/discovernature/out...