There's no way of knowing which of the Sedgwick County Zoo's nine chimps discovered the unlocked door Saturday night, but when zookeepers arrived at the Koch orangutan and chimpanzee exhibit early Sunday, all nine were exploring the zookeepers' maintenance area.
Eight of the chimps, including 10-day-old Mubasa, were quickly ushered back into their main exhibit area.
But Marbles, a 40-year-old chimp, dawdled for two hours, playing with the keepers' brooms, mops and squeegees.
"If you know Marbles like our members know Marbles, he was quite content. He was having fun," said Christan Baumer, spokeswoman for the zoo. "He was pushing the brooms and squeegees used to clean windows."
Visitors who arrived at the zoo before 10 a.m. were given a choice of returning another time or waiting indoors until Marbles was back in his exhibit.
Finally, zoo officials used a tranquilizer on Marbles and carried him into his bedroom.
Within an hour, Baumer said, he was awake and busy with the other chimps.