Hang on a minute! Let's say I am at the ballet for the evening. One dancer particularly catches my eye with his grace and movement. I lean over and whisper in my wife's ear..."He is a butterfly!" She nods and understands. But DL doesn't appreciate ballet, hence I was marked "wrong" for translating "È una farfalla" as "He is a butterfly". Seems harsh :-)
No, in english, animals are referred to as "it". However, as I said in my first comment, people can choose to refer to them with "he" or "she", but that is under special circunstances - usually personal feelings towards the particular animal or a species. But, from an objective, following-the-rules point of view it's "I saw a butterfly. It was beautiful".
If you would have read the OTHER comment above, it said that in English, animals are an "it" and never a "he" or "she" in the grammatically correct sence. In other words, it means that when translating into a language that insist that non-people are all "its" and that animals, birds, fishes, marine animals are all "its" we can not say "she" because we can not pretend we are talking about a Vegan or homo sapian and their "pets".
I wrote the capital letter 'E' plus an accent next to it like -- E' -- to simulate the capital letter e with grave accent on it. Duolingo has signaled it as a warning. Although Italian keyboards do have vocal with accents for Italian characters as keys, they don't have the capital counterpart. Maybe Duolingo can accept the capital letter e with apostrophe after it as transliteration for capital letter E with grave accent on it....