If you haven’t been around them much you may not know, but horses tend to try to bite each other like every chance they can. It’s crazy. Even horses that have been stable mates their whole lives will try to nip at each other as soon as they can.
Maybe it’s a love thing? (not likely)
I almost got bit by a foal. It was teething.
Rarity: NO YOU DON’T!
As far as behaviors go, ponies and horses pretty much behave the same way. My mother in law owns a thoroughbred horse/welsh pony mix, and she says with horses and ponies. They don’t seem to differentiate, honestly.