You can tell you don't have someone's undivided attention if their eyes start to stray."
This may be particularly true if their focus veers away from you or towards other individuals in the room
Also, looking at someone's hands can give you a good idea of how attentively they're listening.
"When someone aren't paying attention, they could jiggle their hands or entwine their fingers.
A person's body language during a discussion can reveal a lot about how well they are listening.
"Humans who are listening to one another are demonstrating body awareness by turning to face or expressing the person who is speaking.
Just having the impression that someone is not paying attention to you is one of the top body language indicators.
" Most of the time, as humans, we can sense when we are being tuned into or when we "feel sensed."