Mesh or Noel Guard for birdhouse/Bluebird box used to deter climbing predators like raccoons.  Handmade from hot-dipped galvanized hardware cloth.  Made by a 26-year veteran of birding, especially with Bluebirds.  Building plan endorsed by the North American Bluebird Society and various state Bluebird societies.  Extends 6.5 inches from hole in birdhouse to make it more difficult for climbing predators to reach in and snatch eggs and baby birds.  Free hardware and shipping