Do new benign moles appear full-formed over night? or do they grow into their eventual full-size?

Grow to a size.: If you have mole or moles, you may watch and wait. If the mole doubles in size, becomes irregular in size, shape or color, bleeds, ulcerates or develops a nodule, see a doctor. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Drink enough water daily so that your urine is mostly colorless. Practice safe sex.

Benign Moles : Benign nevi ("moles") do grow fast. Female estrogen enhances them. The mole may continue to grow for some days before it reaches full size.