So what is going on here? Are these horses mortal enemies? Both horses have their ears back. Clearly biting each other.
One or two pieces of body language should not be taken as a clear signal for anything! Lets see if we can triangulate the body language. We can see the language of the head (ears and mouth). Lets look at the rest of the body. Can you see how their feet are grounded? The horse doing the biting is actually standing with all four feet completely on the ground. The horse on the right has weight pretty equally on three legs and it looks like his foreleg is only lighter because of the position of his head or we might be able to say he is moving forward into the space of the horse on the left. How about their tails? Are they relaxed and quiet or are they full of energy?
Next lets look at the energy of these two. Is it mirrored in each other? Does one have more energy than the other? Is it moving forward, back, up or down or is it staying put? We can look at this one still photo and see if these two have been sweating; indicating previous movement or high energy levels.
Now lets look at this next photo;
What do you see here? Friends or enemies? These horses have their ears back and one is biting the other. Lets go ahead and triangulate the body language.
Are their feet and legs grounded or are they moving? The horse on the left only has two legs on the ground and the horse on the right has all four legs on the ground, but those hind legs are coiled up like springs ready to jettison into the space of the other horse. What about their energy? Is it high or low? Are the horses mirroring one another? What about their tails? Can you see the energy in the tail of the horse on the left? If you could zoom in close on these two, you could see their coats look dry indicating perhaps they have not been sweating.
The first photo is of two friends (geldings) who have lived together for years near Kalispel Montana. The second photo is of wild stallions fighting in the Namib Desert in Africa. The most discernible difference in their body language is energy.
Follow the below link to an interesting article that links the effects of energy on the body. http://en.wikipedia.org/wiki/Somatic_psychology