A parrot should not eat peanut shells, that it is doing so may be from an event in its early learning to eat after being weaned, it could have been hungrier than expected and consumed all it could get into its beak, it could have been given solid food sooner than it should have.
When customers come into the store and select toys for their baby parrots I recommend that they avoid the soft, shreddable stuff like Wesco Kabobs due to the easy ability to eat it. A baby parrot just wants to fill itself up, they have not learned what is real food and what is not yet. Later, when they learn, they can have toys that are meant to just chew, destroy and spit.
Some birds never learn and as such we have to watch them carefully and what they eat and play with. I am sure that every parrot has different intelligence levels like humans.
Our Popcorn LOVES the fortune cookie wrappers and will spend 15-20 minutes pulling and ripping until the cookie falls out, then abandons the whole mess.
She does not eat the cookie but likes to make a mess, if we take the wrapper and flatten it out and look closely, none of the wrapper is missing, she just likes to do it.
Considering when we got her she did not know how to play at all, she now is adept at destroying a small toy with 15 wooden spoons in an hour. They lay in splinters at the bottom of her cage ignored, but are so happy to do so. It is this toy
And they are free with your Chinese meal. LOL. I want to try straws with paper wrappers next, my last parrot Sunshine LOVED them.