UNIQUE SLOT DESIGN
Songbird Essentials Bluebird House-- Slot Entrance Hole
Slot entrance design discourages sparrows.
Researchers at University of Kentucky have reseached and found that bluebirds actually prefer an entrance with a slot like the one on this house, while House Sparrows don't. Bluebirds have a better chance of nesting successfully when House Sparrows aren't interested in the bluebird's nesting box.
Great design for Bluebird Trail
Easy open for monitoring and cleaning.
Ventilation and drainage holes.