"Nothing moved but his eyes, and he flicked them back and forth; a steady fixed gaze was oddly noticeable to the one you were staring at, like brushing a feather over the nape of the neck."
-SM Stirling, The Sword Of The Lady (New York, 2010), Chapter One, p. 4.
Is this true? I suspect that it is. Although my mental processes are entirely logical/linear/abstract/verbal, I have sometimes felt danger when there was danger. Enough people refer to the sensation of feeling eyes at their back. But how does it work? There must be a great deal still to be learnt about organism-environment interactions. There are many more senses than the "five."