Sources indicate that Ben planned to eat practically a whole barnyard's worth of animals last night (and a lamp), but no mention of duck! Could it be that Ben is so repulsed by ducks that he refuses to eat them? Or perhaps just the opposite: maybe he hates all non-duck animals so much that he angrily eats them/yells at them/never plays Halo: Reach with them.
More info as it develops. For now, one thing is for certain: Ben is not duck-neutral.