Believe It Or Not – Surely All These Animals Greatly Outlive You We know the life cycle; an animal is born, grows up, becomes an adult, reproduces, ages, gets old and finally dies. This is a universal truth about animal life on earth. Aging is a natural process for all living beings. In biology, it called senescence. Birth slowly becomes death by way of aging (if not by accident, disease or falling prey) in a natural life process. Therefore, it is hard to believe that some animals are almost immortal. There are a few species of animals in which the process of aging is extremely slow. Their life span is much longer in comparison to that of a human being. This is termed as “negligible senescence”. Here the symptoms of aging are so faint that it seems like they can never die.