Seven clever chimps made a bid for freedom when they fashioned a ladder out of a tree to escape from their enclosure at the Kansas City Zoo, zoo officials said.
One of the chimpanzees apparently leaned a log or a branch against the wall of their compound in the zoo's Africa area and then gave the six other primates a leg-up to the top, zoo director Randy Wisthoff said.
“We had a ringleader,” he said.
“He got up on the log and got some others to join him.”
But despite the animals’ ingenuity they did not have any contact with zoo visitors, as they only escaped into an area reserved for zookeepers, Wisthoff added.
Using food to entice them, staff managed to herd the wayward animals back into an indoor enclosure - after they had been on the loose for around an hour.
Visitors were held in various buildings to keep them safe until the chimps had been recaptured.
Wisthoff said zoo staff regularly check trees in in the area of the chimpanzees for fallen limbs but in this case a chimp apparently pulled a log or large limb out of a tree.
“Chimps are so much stronger than humans,” Wisthoff said, adding that they are also very smart.
There are 12 chimps in total at the zoo, which was closed temporariliy following the incident on Thursday.
Additional reporting by agencies