I’m sure my neighbor has no idea that birds have built a nest in his gutter. It’s two stories off the ground with only 10 feet between his house and his next door neighbor. About the only place to see it is from my back deck, where we enjoyed watching the birds hard at work for more than a week. Obviously, they brought some live vegetation and with all this rain, it really grew. And, I’ll bet the nest is pretty well stopping up the downspout, too!
So, the moral of this story is to be constantly alert to the ever changing elements of your home. Wind, sun, rain, and yes, even animals, can cause changes that warrant your attention before real damage occurs.