I'm back with more questions

My first is Lando is still biting sometimes it seems as if hes doing it on purpose

when i get him out of his cage he step's up and comes out nicely,but when im handling him he (not always) bites my knuckles and any other skin on my fingers that he can squeeze


My second question is about diet,Lando is on a Walmart Parakeet seed (not sure of the name) just got a zip lock bag of it when i purchased him,and Suko is on a 50/50 mix of Tropican Cockatiel Lifetime Granules and Tropimix Lovebird/Cockatiel (also what she was on when i purchased her) can i slowly wean Lando onto the same food as Suko? (is Suko's diet good?) they get human food as well but this is their base diet.Let me know what you's think
