Answer:
Klein created a machine that gives birds a reward (peanuts) for depositing a coin.
Explanation:
Source:
https://www.npr.org/templates/story/story.php?storyId=87878028#:~:text=Inventor%20Trains%20Crows%20to%20Find%20Money%20Hacker%20Josh%20Klein%20wowed,crows%20to%20save%20human%20lives.
