I was explaining to a friend how to use nouns with numerals 2, 3 and 4 and figured out that I don't know which of the following two possibilities is correct:
1a. Я вижу две вороны.
1b. Я вижу двух ворон.
In other words, should I use feminine nouns that denote animals as if they are animated (1b) or not (1a)? For masculine nouns it seems to be clearer, I'd say that 2b is better than 2a:
2a. Отец зарезал три барана.
2b. Отец зарезал трех баранов.