I saw a nest of a song sparrow in the cardboard box in a deserted shopping cart! It was this summer. I saw the sparrow parents fly in and out of the box for a few days, so I approached the box and saw a birdie. It flew out as soon as I opened the box. There were still 4 eggs in the nest. But as I checked the eggs, I found out the eggs were already dry. No birdies would hatch. TOO SAD. High temperature had already killed them before they could hatch.