You're not going to believe this - but all I have to say to get my ducks back into their pen, whether they are in the pond or foraging, is 'Inside'. If there is a hawk or eagle circling, I say 'Hawk - Inside' in a very scary voice and they RUN to their pen. I have trained my ducks on certain words using meal worms LOL. My family and friends are absolutely amazed at how they respond to commands - ducks are SO smart!!! And mine will do anything for meal worms. Now they respond even when they don't get a treat after... They also know that everything good comes in a red cup - so if they are ever giving me a hard time, I shake the red cup and they respond.