Reptile & Amphibian Forums

I just noticed recently that my California Kingsnake has a couple scales that look like they're turning black. I called the vet immediately and she said that it was not an emergency situation, but to moniter it. Apparently she's been "pacing" around the tank and has worn out a very clear trail in her eco earth. She's not lathargic, she's active and there have been no changes in her eating, but those scales just really scare me. Any advice or information would be greately appreciated. Thank you.

The two scales that look like they're turning black are right next to each other. Also, she is sometimes sort of twitchy when we handle her.