Thank you both. On the subject of feeder– it is at the other end of the deck from the box. I have a neighbor who puts out lots of seed (I mean really a lot) so the other birds (including sparrows) congregate there, and I see mainly bluebirds, robins, and mockingbirds here. I started by just putting the worms on top of a hanging basket but had some very aggressive robins dominating. The mockingbirds are plenteous, but they would wait for bluebirds to leave before chowing down. I don’t have the funds for a formal feeder, but I came up with a solution. I happen to grow gourds, and had a nice martin gourd. Low on the gourd, about 1/2 inch from the bottom, I cut a slot on each side the same size as is on a slot nesting box. This has been very effective– the bluebirds can hang on the side, or get in. The robins and mockingbirds can get their feet on the edge, but cannot get their heads inside, so they have stopped coming. I see an occasional titmouse, but that is all. I can’t do live mealworms right now (would you believe someone gave me 10 pounds of dried worms!). When I water my gourd patch, there are worms and bugs that come up, and many birds visit then.
This box has been very popular, though it is so close to the house. We had one nesting already with 5 babies successfully fledged, and they came to my feeder regularly for weeks. That pair then nested in that remote box; this is a different pair in my close box.
Thanks for suggestions and help. I will post updates…