The phrase "inborn instinct" refers to a natural behavior or ability that a living being possesses from birth. It means having an automatic and effortless understanding or skill without the need for any training or experience. Full definition
(ref) When we teach our cats to urinate in one specific area, we are going against these natural, inborn instincts of our cats. (2ndchance.info)
The American Kennel Club recognizes the Sheltie and the Collie as two distinctly different dogs, both with inborn instincts to herd livestock. (animalbehaviorcollege.com)
If you're not as creative as you'd like to be, you might tell yourself that you lack a certain something — an inborn instinct for creativity, a natural talent for fresh ideas, the personality needed for creativity. (inc.com)