Why do living organisms spontaneously replicate itself or "procreate" (my understanding is that it does).
From a uni-cellular and micro-organism point of view. Is there some sort of stimulant in the environment? A chemical reaction that causes it? Is is there a physical or emotional motivation? Is it by choice?
Note: I may have some terms used wrongly as I am not a biologist. In this question, I am interested at living organism nearer the forms of single smallest unit of life form.