The average person may have up to sixty moles by age 25. One or two are present at birth, while most develop during life. With time moles have a tendency to enlarge and stick out. This is perfectly normal. The majority of moles will never cause any problems. However, changes in moles or any other spots on the skin can indicate skin cancer. Moles that are asymmetrical in shape, have irregular edges, are more than one color, are bigger than the eraser of the pencil, show unusual thickening, or grow dramatically within a short period of time should be checked by your dermatologist without delay. Also, persons with multiple moles should have their moles documented and be instructed in how to perform regular self skin exams.