They're invading! Tiny aliens ply our waters looking to take over!
Okay, maybe not. But somebody IS building mock vessels of war and releasing them in the retaining ponds near the Walmart here in DeKalb. Releasing and moving them about, as I've observed different numbers at different times in four different retaining ponds. This is a long shot of the pond near Lowes, showing five of them (the farthest is hard to see, way at the far corner).