Chicken instinct is to drink from standing water; ANY standing water, so they will. It doesn't matter if they have plenty of water or not, they'll hit every place they learn has open water. Ours used to do this even when we did have a fount for them, but we quickly got sick of the tedium of cleaning one of those things properly and switched to a 5-gal bucket with nipples. They're fine. They have access to them whenever they want and always have plenty of water. Due to one chicken having foot injuries, we had them all locked in the run and barred from free range for almost two weeks; they had nothing to drink from except nipples, and no one shriveled up and died (so they must of used them)!