We have several large crows that have built a 'home' in our woods, which we've been tolerating (even when they pick in our rubbish) because they attack and chase off large birds like hawks who get anywhere near it, which makes our birds safer. We have had no issues with the crows and our own animals... however. Our female ducks quack their heads off whenever they see or hear the crows. The male duck and the chickens don't care, but for some reason all of the females freak out and let out their alarm quack. Now I've seen videos of crows going after ducklings before, so is it just the females and their natural instinct that recognizes the crow as a predator of their young? (they have no ducklings and have never brooded). These crows are really big, so maybe they think they're a threat to them as well? Just curious, because I go out every time I hear them give an alarm quack to make sure it isn't an actual predator.