Yes, I live in central Indiana. My bluebird antagonists are House Sparrows, so I’ve put out 4 houses for them to choose from. Usually the bluebirds pick a certain one, but this year the Sparrows started building there. I keep taking out their nest, but they build new ones back. You’d think they’d take the hint. Anyway, Billy and Betty Bluebird (I name most all of the birds I have regularly) chose a different house next that one this year. I have successfully had bluebird babies the last 3 years, and hope they keep choosing one of the 4 houses I offer. My home is in a semi-rural area, just on the outskirts of a small town. I feed the bluebirds mealworms year round, and they visit daily except during when they are teaching the kids where the regular insects are. Then they come back to the feeders after about 6 weeks off. They stay throughout the winter so I’m lucky.
Nice you have had success! We have no sparrows hardly at all. Just the stinkin’ wrens, nasty birds.