We got our chicks yesterday and this is our first time having chicks. One died yesterday and it had what I assume was the dried yolk sac on it's lower bum. Not the vent for sure. I noticed another one has the same thing. He also has a pasty vent as well as one other one. How do I clean the vent? It is dried on hard and wiping with a damp cloth doesn't seem to be working. Could I use a bit of vaseline to soften it up or would that cause problems. HELP!! I don't want to lose any more. We now have 15 buff orpingtons, 4 dark brahmas, 4 australorps and 3 ameracaunas.