I was just wondering if the koi's whisker are
sensitive to vibration
the other day i threw an earthworm in the pond and the it
burrowed under the algae
i dont know how the koi knew it was there
so i guess it has something to do with the whiskers

I know that my Koi respond to anything that falls or gets dropped into the water. I think they have excellent senses in general so I don't know if it is from vibration or smell/sound maybe.