Film analysis - Eight Below: How to show animal character's emotion in film?

Eight Below is a very impressiveness movie. The story is about how eight dogs survived in harsh South Pole without human's help. South Pole's winter is totally terrible, however, these dogs still survived depend on their intelligent and honest character. When they find their master comes back, they are exciting and never blame. After watching this movie, I do believe the dog is human's friend.

Now, I will analyze the emotion in this film. Because this is a film about animals, I can study how to show animal's emotion by it.

1. Body language

Body language always to be an important way to show character's emotion in the film. Even in the normal film, human actors also will use body language to present emotion, specifically angry and excited. Naturally, this method can be used on animal characters. 

However, animal's body language is different from human's. How to make the audience understand animal's body language? That will be a problem. Let's watch a segment of Eight Below here:

In this part, we can see three dogs use their body language because of the food. They can't speak. Audiences didn't know what is this body language meaning. But we still can understand. Why? 

I consider there are two reasons: The scene and the general knowledge. In this scene, we know they are eating. What will happen when they are eating? Eating, sharing or seizing food. According to our general knowledge, we know the dog's body language is about these three things. Then, the first dog's emotion is unwillingness, and the second dog's emotion is willing to share. They use body language let the audience know their attitude and emotion.