I have two female ducks and two hens that live together, they all started laying on Valentine's Day. We had a male duck until just recently, so the duck eggs should still be fertile. We are going to leave the eggs and see if one of the ducks will go broody. There are four duck eggs in the nest. Yesterday, I went out to find the nest uncovered with a small chicken egg right in the middle. Today I went out and found the nest uncovered again, with what looks like a chicken egg in the middle, but it's HUGE. Bigger than the first two duck eggs, maybe even all of them. Is it possible this is actually a duck egg? My buff duck laid the white eggs, and my other duck is a khaki Campbell. So I'm wondering if it's possible this could be an egg from her, or just an oversized chicken egg. I'm new to chickens and ducks so anything is helpful. Thank you!