Chick with a ... belly button?

[t8rtot]

This chickie is about 6 days old. She had this nubbin when we got her.
I got her from Orscheln on March 17th.

Day one at home - March 17th
- - - - - - -

Today - March 22nd

It's dry, not sticky or anything.
What else can I tell you? Thanks for your help!

 

[paddock36]

I wouldn't worry with it as long as any other chicks aren't pecking at it.