LOL, Blink but its yeneh g’lechter (means: no joke, for the english speaking crowd.)
We do have a way of keeping our hands on the pulse / a sixth sense that defies the outside world. I remember a few years back there was a group under federal investigation in BP and one Friday, in walks a person to the mikvah which normally a chatterbox. Somehow, we all sensed that this newcomer is not a tribe member, and you could hear a pin drop it was so quiet. Not so much in what he said, but the way he said it, and the way he carried himself.
We just felt something off (and never saw him again after that)