3 Answers

How to Stop a Horse From Biting & Ear Pinning
By Amy Hunter, eHow Contributor

Biting and ear pinning are methods that horses use to communicate with each other. When they bite or pin their ears back, they are saying "back off." This behavior is acceptable when the horse is in his pasture, but not while being ridden, and not when it is directed at humans. Patience and firmness are important when curing the horse that insists on pinning back its ears or biting while being worked with.

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You let nature take its course .Very young colt .You were a young as well what did you get up to ?

As he is still intact, these testosterone driven behaviors of slight aggression are present.  Once he is castrated, sooner the better, this will not be reinforced, and will eventually end.  Make the appointment with the veterinarian today.