One of our favorite things is to watch the birds in our back yard. When we moved in I put out several “bluebird” boxes and immediately had numerous young blue birds around the house all summer. Last summer it was even better as we had at least two sets with young and one had two hatches… This spring has been different. One nest box was attacked by Sparrows and one of the Blue birds killed. Two other nest boxes were staked out and “owned” by sparrows. the first Bluebird box had a next as we watched the activity waiting and then one morning I found the door pulled open and the next empty? not sure what got that one but expect it might have been