What's wrong with the yellow bird pulling thin?

The yellow bird is usually due to eating spoiled foods, or it is a stress reaction.There are generally two cases of eating spoiled foods. The first is that the place where food is usually not good is not good, resulting in the deterioration of food. The second is because the feed has not been replaced for a long time, and the feed deteriorates in the tank.So pay attention to checking and replacement.If it is because of the stress reaction, you can recover without worrying too much.