I noticed this a couple weeks ago, but I haven't bothered to take her to a vet or any such thing since it doesn't appear to be detrimental to her health, and there's no bleeding.
Basically, she's missing a spur.
She still had both spurs after her last shed, so I ruled out that one of them fell out during the process. It just went... poof. The only thing left is a tiny little hole. Like, for example, the hole you would get after popping a stubborn little zit on your forehead. (Hahah, sorry, gross)
Main question is, do they grow back? Like how sharks constantly lose teeth, and they just regrow. And should I be worried?