That's the difference between human and animal - we have a choice, they don't! We have to look after our stock, they look after their cubs. We may think about it and feel sorry about the life we take (I had the thought about slugs and snail, Sandy, we're just softies!), they can't.
But regarding the birds' diet, I was wondering about which leftovers were ok for ducks, does anyone know? At the moment they just get some veg, occasionally bread. pasta, rice, etc., & egg shells. No other cooked stuff so far until I know better.