I have a Nelson Auto water - the tall steel tube type. This VERY DRY summer, crows have began to drink out of this waterer. I wouldn't mind, except they also POOP when they drink, and also, whatever diseases may be contained in that ... Ugh.

Anyone got any ideas to stop this? Safe to assume, anything I could use to scare Crows (who are very smart) would also spook the horses away from the waterer...

Any help or advice appreciated!