I set out mealworms for bluebirds a few months ago and got no interest from them. I decided before investing in a bird bath, I would try a makeshift setup to see if they would use it. I used a plastic plant tray with a big rock anchoring it. When we left on vacation two weeks ago, I focused melted Browning #6 on it. I reviewed the results today.
The melted Browning snapped 7,372 images with relatively few false triggers. Most of the subjects were bluebirds, but I also got various little brown birds, a goldfinch, a meadowlark, three flickers, robins, deer, mice, and even a dog and a cat. I'm only posting the flickers and the meadowlark because I think those are the most significant. I could post literally thousands of bluebird images but I need to get better image quality than the melted Browning provides.