baby chewing?

Allison • Wifey to 👨🏼‍🦲, mommy to 💙👦🏻, ivf warrior 💉, 🌈 baby 💙👶🏻
My 19 wo son today looked like he was chewing a wad of big league chew 😂 nothing was in his mouth. Anyone else's baby been doing this?