Especially great is the realization on Flik's face as he realizes that Hopper's afraid of them: "We're a lot stronger than you say we are.... and you know it, don't you?"
The first time Atta had to speak to Hopper, she was trembling and stuttering and could barely even look at him. When the bird crashes and burns, however, and the Blueberries come stumbling out coughing and choking and helpless, she plants herself in front of them and looks him square in the eye. You can see it in her eyes. That's when she became a queen.
Atta: Get behind me, girls, it'll be okay.
The best part is that her voice wavers as she says it. She's terrified. Who wouldn't be? But those are her kids, her sister's best friends who were risking their lives to save the colony. Nobody is messing with those ants without going through her.