I feed last night at 5pm when I got home everything was fine all ran up to the gate waiting for their second feeding for the day when I went to put them to bed at 8 one of my ducks was waddling like he was drunk and flipped on his back feet kicking like crazy. I righted it same thing again and three more times. placed it in a nesting box and it settled down and a 10 was still in the box still alive and looking fine any idea what causes this? I was thinking it's air bladder might be messed up for the onset to be so quick not knowing if it and the rooster had a go around.