I have a similar blue bucket that I bring into the coop/run to clean. I put poop in the bucket. The chickens are FASCINATED with the bucket. They peck at it, try to perch on it, constantly look inside to see what I'm putting in there (poop! no, you don't want it, chooks!), etc. Yet, they have an almost-identical bucket (same size/shape, just orange) inside their run that has water in it for them, and they don't give it a second glance, unless they are drinking from it. Chickens be WEIRD.