If you've never seen alpacas fight, it is quite the sight. They first start and seem like they are playing. They will kind of pick at each other and wrestle. Wrap their necks around each other and kind of chase each other around. But, as the fighting continues, it gets more aggressive and they start biting each other.
Male alpacas do have something called Fighting teeth that need to be kept trimmed. These come in once they are an adult and can be very sharp. In the wild, these are used as defense against other alpacas to determine dominance and earn the right to mate with the females. On farms, it is best to keep these trimmed to make sure no harm comes to any of your other alpacas if they are fighting for dominance.
Another thing they will do is rear up and throw themselves at each other trying to knock each other down. When they are in fighting mode, they are totally unaware of almost anything else around them. It's usually not a good idea to get in the middle as it would be very easy to get run right over if they are running and biting at each other. This fighting can last for a few minutes to picking at each other periodically all day long. Sometimes one male alpaca might end up trying to pick fights throughout the day with any and all of the other male alpacas.
In regards to human safety, common sense plays a big role here. They would not intentionally try to hurt a human being. Only way you could get hurt is if you got in the way while they were fighting.
For the most part, alpacas are very sweet, lovable creatures and would not harm you.
Please feel free to ask questions or leave comments.
May God's Grace and Peace be with you and I hope you all have a great weekend...