 When cats mate, the tom bites the scruff of the female's neck as she assumes a lordosis position which communicates that she is receptive to mating.Cats communicate olfactarily through scent in urine, feces, and chemicals or pheromones from glands located around the mouth, chin, forehead, cheeks, lower back, tail and paws.Their rubbing and head-bumping behaviors are methods of depositing these scents on substrates, including humans.