I've got a couple of these too, they are really good but not 100% weather proof. Granted, we get some pretty severe weather up here, and I've only noticed a problem when the rain has been blowing straight towards them. Water collects a little bit in the bottom of the hopper then and the pellets can swell up and not flow properly. I usually check this by stepping on the treadle each morning, especially when there's been rain. Undercover, there wouldn't be a problem at all. Rats can't get in, but my wyandotte bantams can manage fine. I don't think anything much lighter than that would manage it. Crows and magpies? Not sure, don't get big numbers of them up here.