White House visitors were visibly startled Thursday when they were unexpectedly greeted by first lady Michelle Obama.

Mrs. Obama, with the help of first pooch Bo Obama, greeted each of the tour guests as they filed into the Blue Room.

"He's loveable," the first lady said. "Bo is like the kids, he's usually more exciting than me."

The surprise appearance came on the two-year anniversary of President Obama's inauguration. The gesture is part of the first family's commitment to making the White House more open to the public.