I put up my extra boxes near the edge of my yard. I tried to place them so they would have morning sun and afternoon shade. I placed them far enough away from trees so predators don't have access to them. So far I have two pairs of Black-capped Chicadees nesting in them. One has six hatchlings, and one has five eggs. I have never had a Carolina Wren nest in one of my boxes, but I have had them nest in my shed.

I discourage the wrens. I take any sticks they put into a box away as quickly as possible. From the information I've read on the Sialis website, if you let wrens nest, you will soon be overrun with wrens. The wrens will poke holes in the Bluebird's eggs, or toss out their chicks. So if you're trying to get Blues, I would certainly discourage the wrens.

It was raccoons that got the first failed Bluebird nest, because they were good sized nestlings and one morning they were gone. So something got them overnight. I then baffled the snag using sheet metal flashing, and that DOES work for all climbing critters, but that didn't stop the House Wrens who got the final nesting. I knew it was wrens because I found an eggshell on the ground that had a tiny hole in the shell, and the Wrens were flocking around the nest hole later in the day (poor Blues). Dante, I can't speak for Lisa, but I don't "eradicate" House Wrens as they are native birds, just don't encourage them. They like brushy, shrubby areas (as do many birds, such as Cardinals and all Sparrows), and I've removed most of that. Also you can remove their sticks from a nestbox where they start to build a nest. Goldfinch, when the Blues were nesting, I did do a little House Sparrow control. I had a nest box installed on the side of the house that had a Van Ert trap in it. There are not a lot of House Sparrows here, but that did remove a couple of males that were trying to nest in the yard and may have posed a threat to the Blues.

I'm really sorry your babies were taken and the nest destroyed. Is the nestbox on a metal pole with a baffle? If not, that could be the problem. Raccoons are everywhere, even if you haven't seen one. If the box is mounted on a wooden pole or a fence it is easy for a raccoon, a cat or any other climbing animal to get to it. If you haven't already looked at the sialis.org website you should spend some time reading and make sure you have a proper setup. You know, even when you are being really careful sometimes tragedy just happens. I don't put out any feeders at all because I'm afraid of bears coming around for food. I know the birds have plenty of natural food and if they can't make it out there then maybe they shouldn't.