Eyes had picked up on the sound of movement quickly enough, but he wasn't exactly expecting it to be Hibiki when he looks toward the direction it was coming from. Nor was he actually expecting her to try to throw something at him.

... Not that it really mattered in the end, that snowball wasn't going to hit. But considering who it was that threw it, it was mildly impressive. But he still raises an eyebrow at the fwump sound it makes. So close, little snowball...