These are some of the bird houses we have around our property. People give them to us, we bring them home from the dump and we get them at yard sales. Of the sixty or so 'units' available, not one bird has ever nested in one of them. Not ever. They do nest in the Baltic Ivy that covers one side of the house. They really fancy nesting right over the kitchen door so that when we come in and out they can dive bomb us, squawking and screeching for us to get away. Nice. Real nice.