geese (and ducks?) are incredibly particular about water depth!! they fear turtles and other pond life threats. i have geese that rejected certain ponds in favor of the kiddie pool for years. then one day you'll find them swimming! if a pond is deep enough for a human to swim it may not be suitable for water fowl who prefer shallower swimming. finally, everyone benefits from being locked up at night safe and sound. just takes one nasty thing.