A trick tank is a watering device for livestock or wildlife. It collects precipitation, holds the water in a covered tank to minimize evaporation and maintain adequate water quality, and dispenses water on demand into a basin from which animals can drink. Dispensing may be regulated by a mechanical float device similar to a ballcock in the tank of a flush toilet.
Trick tanks are manufactured in several styles, including inverted umbrella and apron. They are heavy and often are used in remote wilderness locations, to which they may require delivery via helicopter.
To provide water to wild animals, not livestock, fencing may be built to surround a trick tank. Fences serve to exclude cattle and sheep. Trick tanks are widely used in the southwest United States, where periodic droughts may cause population crashes in game animals unless water supplies are provided.