Most of the babies survived. Though I sometimes wondered why. If the houses hadn’t been real wren houses, the starlings would have just reached in and snatched them. I certainly saw them try enough times.
They are recklessly brave though. We inherited two wren houses at our last house, so had wrens in the backyard almost every year. They were so ready to face down any threat, including people, I always found at least one a season dead on the patio. The neighbor had outdoor cats.
(Gasp!!) I’ll try . . . NOT!