Can Corals Adjust their Sting?

[SteveMM62Reef]

I have a RBTA, it kept moving over towards different Corals and they would close up. I’d make it move away. Then it would be right back in a few days. Now I noticed it is right next to the Coral but not touching it this time, and the Coral is out. Did the Coral adjust it’s sting?

 

[SlugSnorter]

what? I don't understand.