We have four pekin ducklings. They are from the same hatch, but were separated at 12 days old for about 4 weeks. They are now back together. My concern is, the two that were separated off have very faded, white bills. The other two have vibrant, healthy looking yellow bills. I don't know of any change from their routine when they weren't with me as far as type of food. Can anyone tell me why they're bills would be a different color? They appear normal and healthy otherwise.