"They might use the brute force method and come out and knock it down on the ground and see what they can scrape up with their teeth and their fingers," said Maureen Leahy, Lincoln Park Zoo manager of primates.
Keo is one of the three oldest chimps in American zoos. And, at 50, he's doing great.
"Keo hasn't missed a beat. He's extremely active. He's not at all overweight and his heart is in great shape," said Sue Margulis, Ph.D., Lincoln Park Zoo Curator of Primates.
Chimpanzees and humans have much in common.
"They share, as far as we know, 98.7- percent of the same genetic makeup as humans," said Elizabeth Lonsdorf, PhD, "Incredibly close."
Maybe that explains why Keo, the male, can't see the ice treat right under his nose. But the females? They catch on right away. They are the gatherers and finders. In fact one female, Kibali, 28, stole part of the sculpture from the birthday boy, who didn't seem to mind. He just sat in the shade.
