Only a few animals including humans experience the "aha" moment. That is when there is an attempt to solve a problem and a mental moment occurs when the solution is identified.
Tests were set up for elephants to retrieve food through the bars of their enclosure. Unfortunately, they didn't use poles provided to them to pull the food towards them. When elephant use their trunk to pick things up they lose their ability to smell the food, so they don't bother.
Another test was worked out which left the trunk free: food was hung up above the elephant's heads and objects to stand on were put inside their pen. A young elephant rolled a cube under the food, placed his front feet on the cube then grabbed the tasty treat. He later rolled the cube down a hill, put it under some flowering tree blossoms and promptly stood on the cube to reach the food. This shows application of a concept to different situations. When the cube was taken away he used a tire or ball to reach suspended treats.
Oddly, two females in the same pen as the test elephant did not attempt to reach the food at all. Maybe they weren't interested.
Elephants are intelligent creatures especially when doing forestry work. They know what their handlers want them to do. This test shows that they also have insight into problems and can solve issues that confront them.