The bluebirds have laid a total of 5 eggs in their box and incubation has begun. I haven't actually seen the bluebirds on the nest, which had me wondering if they were incubating, so I lightly touched the eggs enough to see if they were cold and they were quite hot, so they are definitely being incubated. The female is always around the nest box too so maybe in a couple of weeks I will have some photos of nestlings!