How to take care of tadpoles?

i found 2 tiny tadpoles in a watering can in my backyard. im not even sure that theyre tadpoles yet but i think they are because theyre zippin around and kinda look like em. theyre too small to tell though, about the size of the period symbol on a keyboard. its kind of dirty in the watering can and im afraid theyll die. should i move them into a clean bowl? what do the eat, will they live in tap water, and should i move them?