In an odd way, Morgana both recognizes and appreciates the subtlety with which he tries to protect her, but she's never been one to insist upon it, so steps beside him.

If that makes him angry, so be it, but he needs protection as much as she does. Besides, if her moving doesn't annoy him, her suggestion probably will.

"No. They do not want us here. They want us out. That means they're protecting something."

They are bones without real connections, so Morgana is literally hoping that they can only scare, not do any serious damage.