8. Cats are an altricial species, which means that for some time after birth, they’re relatively immobile and not all of their sensory systems are working at their full potential. Strain says cats are born with their ear canals sealed and their auditory systems immature. “They respond to sounds as soon as the ear canal opens, and their hearing threshold will get better—that is, they can hear softer and softer sounds—in the several weeks after that,” he says.