An innate, typically fixed pattern of behaviour is our instinct. A sense of intuitive thought/feeling. An urge, an inner prompting, a drive, a compulsion. That quirky urge, that little voice inside you, those gut feelings is what emerges naturally within you in a particular situation to react with outer world. Every instinct is an impulse. Feel it, trust it, follow it, because when you've whittled down your options and are stuck at a crossroads, that is what gets you through it! That good old instinct feeling!