I put "Die Ente frisst Gemuese" since for animals it's "fressen" and people it's "essen" but I got it wrong...doesn't make sense
They may have changed it, or you may have to use the ß. It accepted "Die Ente frißt Gemüse." for me.
You can use "essen" for people and animals.
And "fressen" is not limited to animals. If you use it with a person it changes the meaning to "to gorge" though.
Hope I could help!
But it's much more common to use "fressen" for animals, I would not usually use "essen" there. That should be changed.