I got a new Khaki lady today to be a partner for my original khaki male. The guy originally told me she was 3 weeks old, but she looks way too small for that. I got her home anyways and set her with my other ducks (supervised) but one of them started to nibble on her neck and the size difference is too much for me to be comfortable with so I took her out. Now she's doing this weird gulping movement with her neck, and (I'm not very familiar with ducks so idk if this is normal) but one side of her neck seems much larger than the other. What do I do about them integrating and is she okay?