parakeet/budgie question

[4NDELIT]

ok guys... I have a question, and I don't know who to ask so I figured I'd post it up here. About a year ago, my mom found a bird in our backyard sitting under a palm tree. It is a blueish little bird, I would say it's a parakeet, my mom says it's a budgie, but that's not the issue. We bought a cage for it, and kept it thinking it was someone's pet, and we'd see signs for a lost bird, but we never saw any signs, so we ended up keeping it. We let it out of the cage to fly around every night, and recently, he's been concerning me. He's always been fascinated with anything shiny (my dad's diamond ring for example), but recently he has started to freak out. He'll sit on my dad's hand, puff up into a ball, stick his head right next to the ring, and spit up tons of seeds. I have no clue why he does this, and I was wondering if any of you guys would know; I think I saw that a few of you were vets.

here's a pic of him joining me for dinner: