The Adleaide zoo was closed and evacuated when Karta, a 27 year old orangutan (pictured above), escaped from her enclosure. She used a branch to climb over the fence in her enclosure, then started building a pile of debris to climb over an outside wall.
About thirty minutes after she escaped, she changed her mind and went back into her enclosure.
"Zoo curator Peter Whitehead told reporters the ape seemed to realise she was in a place where she should not have been.
" 'She's actually hung on to the wall and dropped back into the exhibit,' he said."
"Ryan Johnston, 11, told ABC News he had seen Karta's escape, and described it as 'amazing'. "
" 'You're talking about an animal that's highly intelligent,' Mr Whitehead said.
" 'We've had issues with her before in normal day-to-day operations where she tries to outsmart the keepers. She's an ingenious animal.' "