Puzzle toys for smart birds

My Senegal parrot is too smart for most toys — figures them out in 5 minutes and then gets bored. What are the most challenging puzzle/foraging toys you've found? I need to keep that big brain occupied!

Interesting take! I see your point but I've had a completely different experience. My zebra finch actually...

My lineolated parakeet did this too! Turned out it was because of insufficient UV light exposure, especially in Canadian winters. Once I addressed that, everything went back to normal.