Buzzing?

So dusty has been running around all night, climbing all over me, sniffing me, actively nudging my foot. Basically, letting out all his zoom is and using me as a hurdle. And I noticed sometimes when he’s running near me, he’s making a buzzing sound. I’m not exactly sure what that means. I low-key thought there might’ve been a fly but turns out It’s just him. Also, any thoughts of how old he might be I got him from the Amish so I’m not exactly sure.