Black spot on comb

[SusanPC]

Not sure if this is normal or could be indicative of something else. She is our alpha, so I am not sure that another hen would peck her, but can you tell me if mites or some other condition could cause this? Thanks. She is 20 weeks old.

 

[Brookshire11]

Looks like pecking to me...I have a Buff Orp who's second in command, and she gets those often enough.
My "head hen" get them occasionally too