A baby's how-called monkey clutched tightly at the back of an old male monkey, and its little fingers grabbed the fur. But they have nothing to do with, not even the same species.

Scientists found surprising evidence of what they called the monkey kidnapping, while reviewing videotapes from the Panama Island. Capuchin monkeys were seen carrying at least 11 roaring babies between 2022 and 2023.

"This is a shocking discovery," said Zoë Goldsborough, a behavioral ecologist for animal behaviors in Germany, Max Planck. “We don’t see anything like this in the animal kingdom.”

The monkey’s motivation is still under investigation. The cape is a cat-sized monkey found in South and Central America. They live long, smart, and learn new behaviors from each other. A group of curled tongues in Panama even learned to use stone tools to crack open nuts and seafood.

Goldsberg and other researchers at Max Planck and Smithsonian Tropical Research Institute have built over 80 cameras to study the use of the tail roll tool, but were surprised to see the first Howler Babies appear in early 2022.

The video shows the capsule walking on the back and hitting the stone tool with the baby lingering sound. However, the camera doesn't capture the kidnapping moment, and scientists say it could happen in trees, where the growler spends most of his time.

“The window into this story is limited,” said Margaret Crofoot, co-author of Max Planck and Smithsonian. The researchers said the findings were published Monday in the journal Current Biology. Infant howling monkeys are usually carried by their mother while they are still in care. All the babies in the video (from weeks to months of age) are too young to wean.

"The part I have hope for wants to believe that some people escape and go back to mother, but we don't know," Croft said.

The videos record some young capuchin males who are still carrying dead how called babies, which may have died due to hunger. Although scientists are uncertain about the cause, many animals (from gorillas to orcas) have been observed for their own dead offspring.

Why do capuchin men do this? There was no sign of intentional aggression on the babies, they did not eat them, and excluded plunder.

"We all spent hours destroying our brains why they did that," Goldsborough said.

The first baby gripper may have a confused “caring motivation” or parental instinct because he shows tenderness in interacting with the baby, she said. Four other men then copied his behavior.

Researchers say they do not believe that capuchin monkeys intentionally harm babies. So far, only one set of curly rolls has been kidnapped.

The study shows that “behavioral differences between social groups of the same species vary greatly.”