Yes, they do.

depends on the size of the koi and the size of the tadpoles, but yes, they will eat them if they can. Koi will eat pretty much anything in the pond. bugs, algae, plants, tadpoles, baby fish, etc.

My koi got quite big since last yr and the are eating everything I have put in as tho they are starved. I do feed them and they still have destroyed all the plants this yr except of course for the lillies. Now I couldnt find the 2 tadpoles I put in a couple weeks ago. Do you think I could get more and keep them seperate until the get a bit larger and then put them in pond? Thanks.

Maybe if you had bullfrog tadpoles they wouldn't eat them, but I'm not sure you'd want bullfrogs in your pond. They also eat everything!! I have a separate 30 container pond just for tadpoles. My koi ate the green frog tadpoles I got last year so I learned not to mix them.

Some koi will eat bullfrog tadpoles if they can get them in their mouth. I would guess that your koi are not that large as they have not eaten you lillies. Those will be gone once the fish get big enough.
Mike

Must be one big Koi to get something the size of a golfball in his mouth.... eek!!! And so far, my koi have left my lillies alone. They are 1 ft long. But, of course, now that I've said that, when I get home wanna bet they've eaten the lillies? Calling Mr Murphy!!