I don't have bass, and I have seen perch snap them up by accident when eating feed, and spit the tadpole out minus the feed.

Ever notice that the vast majority of tadpoles all swim in the same direction? 9/10 times it is counter-clockwise around the pond perimeter. Only once I saw it going the other way. I really don't know why other than to guess they start in the morning and follow as the sun heats the water in a certain direction.