inner sense of self-preservation inherent within creatures in the animal kingdom; sense of right and wrong for human beings that seems to come naturally; natural intuition to respond, sometimes suddenly, to sensory input; initial strong feelings experienced as new information is processed.
The lion is feared throughout the animal kingdom because of its predatory instincts.
My senses aren't tingling at all -- my instincts have failed humanity!
Guy 1: My instincts tell me I should NOT be doing this, but I gotta be strong!
Guy 2: Dude, you're only bench-pressing like 45 pounds!
If teen-aged males trusted their instincts more, they wouldn't say the (too often) famous last words: "Hey, watch THIS!"