The nickname for city of Chicago is Chi-Town (pronounced shy-town)
That could have been a chant for the city.
A "scavenger hunt" is a game where particpants are sent out with a list of things to gather together and return to the party. The team or person finding the most things on the list is the winner. My bet is that at the White House, the scavenger list will be very controled and geared for young girls.