First lady surprises White House tourists

First lady Michelle Obama surprised tourists at the White House on Thursday, shaking hands with visitors and introducing them to her dog, Bo.

"Thanks for coming to see us!" she told tourists as they came into the Blue Room. She asked people where they were from, shook hands, and gave out birthday hugs. 

"So what have you learned about the House? Give me something, give me a fact," the first lady asked a group of children visiting the White House on a school trip.

"It's big," a student replied. Another offered, "the dog is nice."