This morning during my pasty butt checks I noticed this on one of my chicks I know this is where the umbilical cord was attached but the other chicks hardly have anything where theirs were. This chick also has a different chirp than the rest. Almost like a distress call. She's still acting normal, I saw her eating just a few minutes ago. but I think her umbilical site is infected. It looks dark (necrotic maybe?) Around the tiny scab. It also looked completely normal yesterday. I don't want her to suffer. what should I do?