A few weeks ago i found out my two collared lizards couldn't coexist anymore so i separated them. One was weak because the other bullied it and ate all the food, so i took care into making sure it got water every day and ate as well. It was doing really good recovering and starting to act like normal again. However, i noticed a bump starting on the middle of its head. I figured it was something that would just go away. it's been there for about 2 weeks now, and has grown bigger. It likes to sleep alot under the heat rock, but other than that there's nothing specific i know it does. If you have any advice on what i should do or what could be the problem it would be appreciated. Here's a photo...


