Since I put up bird feeders I've gotten a small population of Chickadees in the yard. I'd like to put up a bird house in the hopes that some might chose to nest in my yard.
Unfortunately, we also have somewhere between 10000000000000 - infinity (only slightly exaggerated) house sparrows that roost in our hedge and mob the feeders. I'd prefer not to supply a nesting spot for them, but I'm too much of a softee to tear the nest out and destroy the eggs if they happened to move in.
Are there a certain size box hole that's too small for House Sparrows but large enough for Chickadees?