text:  I always wonder how they get in there with all that in there. Yeah, they're like mice. They can get into like a three-eighths of an inch opening, it seems like. But, yeah, I've had two of my five boxes. I've had a second fledge of bluebirds, and they just finished up. Yeah, I lost two batches early on. It seems like the earlier efforts are the ones that are most susceptible to whatever.