Hole Reducers or Restrictors
Copper Portals – Kettle Moraine Woodworking Inc
1 1/2 Inch Bluebird Housepredator Guard Entry Hole Protector Portal Protector Solid Steel - Etsy
Duncraft.com: Bluebird House with Pole & Noel Guard
Amazon.com: Bluebird House Predator Guard,Metal Birdhouse Guard,Bird House Hole Protector Guard for Eastern Bluebird Box 1 1/2 Inch Opening : Patio, Lawn & Garden
Audubon Cedar Bluebird House with Pole and Hole Protector – Prime Retreat Products
Wood Bluebird House Predator Guard
1 1/2 Inch Bluebird Housepredator Guard Entry Hole Protector Portal Protector Solid Steel - Etsy
NestWatch | Dealing with Predators - NestWatch
Bluebird House Predator GuardMetal Birdhouse GuardBird House Hole Protector | eBay
Birdhouse Portal Protector - Various Sizes
Nestbox Recommendations
Amazon.com: Bluebird House Predator Guard,Metal Birdhouse Guard,Bird House Hole Protector Guard for Eastern Bluebird Box 1 1/2 Inch Opening : Patio, Lawn & Garden
Portal Protector - Bell Farm Shops
Copper Bluebird House Portal
Got a Fancy Bird House? Why You Need a Birdhouse Hole Protector — Nature Niche
Nestbox predator controls
Amazon.com: Bluebird House Predator Guard,Metal Birdhouse Guard,Bird House Hole Protector Guard for Eastern Bluebird Box 1 1/2 Inch Opening : Patio, Lawn & Garden
Audubon Cedar Bluebird House with Pole and Hole Protector at BestNest.com
Duncraft.com: Duncraft Bird-Safe® Bluebird House & Pole with Noel Guard
Metal Hole Protector Bluebird House With EZ Open Front - Etsy
Amazon.com: Bluebird Nesting House 10 Pcs Bird House Predator Guards Stainless Steel Rings Bird House Hole Protector for Eastern Bluebird Houses Anti-bite Metal Guards : Patio, Lawn & Garden
Metal Bird House Portal Protector Set of 3
Birdhouse Predator Guard - Northwest Nature Shop
Amazon.com: 6-Piece Metal Bluebird House Predator Guard，Metal Birdhouse Guard，Bird House Hole Protector Guard for Eastern Bluebird Box 1 1/2 Opening : Patio, Lawn & Garden
Nestbox Recommendations
Amazon.com: Metal Bird House Guard with Copper Portal for Eastern Bluebird Houses 1 1/2 Inch Opening (4 Pieces) : Patio, Lawn & Garden
Birdhouse 1-1/2” Entrance Hole Predator Guard Stainless Steel flange, Bluebird | eBay
NestWatch | Predator Guards Carry Their Weight - NestWatch
