what does he have in his mouth

I am not only a dog mom I am a puppy mom fishing strange sounding things out of his mouth It sounded like he was crunching down on a lightbulb upon closer inspection, it looked like one of those ten-year-ones I chase him down He loves this! I hear the crunching as he surrounds it with his mouth Is it glass? He spits it out after I rub him under his chewing chin It is only plastic, I feel a relief. He grabs something else with his big face. CRUNCH! The chase is on.