guys sniffing their fingers

My boyfriend does this all the time. He'll scratch his ear & then sniff his fingers. He'll scratch his butt & then sniff his fingers. His balls? Still sniffs them. I asked him about it & he said a lot of guys do it so I'm wondering if you guys have experienced the same with males. I've never been in another relationship before & never really grew up around boys or any males so I really don't know if it's normal 😂 it doesn't bother me I just think it's kind of strange