I've got this sweet duck, I believe it's a crested mallard(?) who starts walking in circles while jerking it's neck usually left. This happened twice, last year. But I had thought it was because he had been fighting with the other ducks and got knocked for a loop. He got over it fairly quickly. We've then had to get rid of the ducks because of the aggression. Now for the last two months, it's been happening every other week. The first time it lasted a couple of minutes. After going in circles, he would sit down and quack before getting up and running off like he was scared. We caught him and tried to calm him, he eventually returned to normal like it never happened. After that, he would calm himself and sit down after going in circles for a little bit. But yesterday and today, he's been having a bit more of a problem. He's had them about five times today, but they never last longer than a minute then he'd go back to doing whatever he was doing. But he definitely seems to not be eating, we've even tried feeding him some meal worms but he won't even come (he usually loves to eat out of the bucket we put it in). And it seems like it only happens every time we come out to fill up their feed or check up on him. I've read online that maybe adding brewers yeast to their food should help, I've added that for about a week now. And before, I want to say a couple of months we started adding some Poultry Cell Rooster Booster to their food for extra vitamins as I believe our chickens are going through fowl pox right now. We're kinda new to owning chickens and ducks, been two years now. And wow, never knew they had so many problems! I feel like I've been scrounging through more BYC posts than I do YouTube videos now haha. Never thought I'd had to sign up though! Any help would be very much appreciated! Thank you!