What made me ask is this. I've got a 1-gallon water thing for 4 hens. I fill it up twice a day. They are either a) drinking like there's no tomorrow, or b) bumping into it all day and spilling it. I can't tell all the time - sometimes there's a puddle, so I know they spilled it. Other times... it's just dry. Either way, they're not dying of thirst, but it made me wonder. ?