Nevr throw stone at birds or nevr throw stone to birds.

Which one is correct?

Never throw stones at birds.

If you throw something 'to...', then you either (i) expect it to be caught, as with two kids throwing a ball back and forth
or (ii) throw food to the birds (or other animals) for them to eat, such as, for instance, throwing food to the pigeons, or chunks of bread to the ducks in a pond.