Today I learned that orangutans can learn to tie ropes.
For example, orangutan and watna enjoy connections in a variety of materials, and even ignores food when absorbed in this activity. No one has taught her to make connections, and she is not rewarded for it-it's just a hobby.
Source: https://www.livescience.com/54780-orangutan-wattana-is-knot-tying-master.html