I'm confused about my mares behaviour?

Whenever my share horse is close to any other horses she is constantly trying to kick or bite them. All of the horses in her field don't dare come near her now and stay out of kicking distance at all times. All she has to do is walk past them and they automatically move out of her way. Only thing is when she sees a horse in another field or in the distance (e.g when we are on hacks) she gets really excited and raises her head, quickens her pace and pricks her ears forward. So does she hate or like other horses? I'm confused????