Feb. 10 (UPI) -- A group of chimpanzees used tree branches to break out of their enclosure at a zoo in Northern Ireland on Saturday.
The chimps appeared to use storm-damaged branches to create a makeshift ladder and scale the walls of their enclosure, The Guardian reported.
Zoo visitors captured video of the caper, as at least one chimp emerged from bushes near the enclosure into a path and others sat near the top of the enclosure.
"Don't escape you bad little gorilla," a child could be heard saying in one video.
Other chimps remained in trees on the wall of the enclosure while some zoo guests were shocked at the sight.
"I was petrified, obviously, having the kids and I tried not to show fear but inside I was a bit like what happens if it attacks us or tries to take the kids or runs over," zoo guest Danielle Monaghan told the BBC. "But we just had to stay calm."
Monaghan captured film of the encounter and said she would "never forget" how the "smart" chimpanzees escaped the enclosure.
Chantal Baxter, another zoo visitor, said her youngest child shouted at one of the chimps when it appeared before them.
"I think she scared it and it did sort of make its way back up the hill," said Baxter.
She added that it was "easy to think it was funny" after the encounter, but that the experience was still "quite dangerous."
Zoo employee Alyn Cairns said the chimps were "quite cowardly" and returned to their enclosure on their own.
"They're intelligent primates and know they're not supposed to be out of their enclosure, so got back in themselves," he said.
Cairns said it appeared the trees in the enclosure had been weakened by the storm, allowing the chimps to use them to climb out.
The escape was the second at the zoo this year after a red panda went missing overnight before being discovered in a nearby garden. Cairns said the zoo would reconsider the layout of the chimpanzee enclosure.
"We like things to be natural in their enclosure, to have trees in it, but we will review it," he said. "We may have to remove the trees or make them a smaller level, although we don't want to do that."