I am not too sure but I know that a person I know sometimes feeds his snakes ducks. I am not sure what species of snakes he has but I know he does raise a few BPs, so it actually may be possible, sorry thats all the info I have to offer.
In my opinion, chicks are not going to be a food source you want to go with unless you have a steady continuous supply. Ball pythons commonly "imprint" on food items. Once they have something different, it is sometimes difficult to get them to eat anything else.
Can they eat chicks? sure. I would stick to mice or rats though.