In 2013 three dolphins approached some divers on a night dive off the coast of Hawai.
One of the dolphins, a baby, appeared to need help. The baby dolphin had a large fishing hook stuck in its tail and a fishing line cutting into the tail.
The dolphins approached one diver called Wayne, who had a look to see what he could do. Wayne found that the hook was too firmly embedded, so he had to steady the baby on the ocean floor and use his diving knife to remove the hook.
While tame animals may approach a human for help, it is very unusual for wild creatures to do so.
The dolphins' actions imply that they understood that humans could could help the youngster in a way they could not, and went to Wayne specifically to ask him for help.