Treat Their Nests Like Weeds
That is to say, yank them out! House Sparrow nests are distinctive for their junky appearance. Imagine a nesting box crammed with leaves, grass, cigarette butts, straw paper and all kinds of other stuff in no discernable order. That’s a House Sparrow nest. If you see one tucked behind your gutters or in a nesting box, pull it out and throw in an outside garbage can. DO NOT TOSS IT ON THE GROUND! The little jerks will pick it up and put it right back where it was piece by piece in a day or two. And if you see eggs in the nest, place them on the ground for a snake or raccoon to make an omelet. Don’t worry, there are a lot of endangered birds in the world. House Sparrows ARE NOT one of them.