Koi are very intelligent fish with unique personalities. Jackie Chan famously trained a koi to roll over for a belly rub in a viral video. Training a fish to roll over is no easy feat, and should be worked up too. Koi develop relationships with their owners, showing excitement when seeing them, and learning their routines. Some Koi will even rub up on their owners hands when in the water and enjoy being hand fed. Certain Koi are naturally more social than others due to their personalities, you may have already noticed a few “greeters” always say hi while the shy guys hang out in the back.