I live in south Florida and we have had an unusually wet summer. This summer I have noticed brown stains developing on the eastern side of my house and mostly in areas protected from direct sun with either overhang or shrubs. It looks as if someone spit tobbaco juice or through feces against the wall. It is present on the paited stucco, wood surfaces and even the glass and metal surfaces of the entery lights. It will scrub off. It is mostly in blotches, but there are some trails also. It makes our entry way unsightly. I have seen no animal life on the wall. All surfaces were freshly painted 2 years ago with a high quality outdoor paint. I am not sure what is causing this and how to prevent it. Any help would be greatly appreciated.