Chickens, an animal, get up very early, and then every day at dawn, they start to crow and absorb the essence of the sun and the moon. So why does the chicken say that it is very tonic? It is because it is full of yang. So chicken is a hot food.
As for ducks, we all know that they play with water. So when we say that they are getting angry or something, they just want to eat duck to reduce the fire and cool down. The duck we usually eat is a cold food.