An animal drinker includes a base tray that is defined by an exterior drinking trough connected to an interior fluid reservoir by a passageway. The trough and the interior fluid reservoir are maintained at a consistent fluid level. An upper reservoir stores fluid above the interior reservoir and is in fluid communication therewith by an outlet positioned at the bottom. A buoyant float pan is positioned in the interior fluid reservoir of the base tray. A float stop is positioned between the float pan and the outlet of the upper reservoir to stop the flow of fluid from the upper reservoir to the interior fluid reservoir at a predetermined level.
