A call stack is used for several related purposes, but the main reason for having one is to keep track of the point to which each active subroutine should return control when it finishes executing.
Though they are commonly mistaken for rodents due to the similarities they share with ground squirrels and marmots, moles are actually mammals. Eastern Mole. The most common mole in the United States is the eastern mole. Adults are typically about half a foot long with sleek, dark fur, long snouts, wide hands, and obscured eyes.
1 The cluster is generally spindle shaped, and scattered.  Spitz Nevi. This type of mole is most common in children, and usually appears on the face, primarily the cheeks. The moles are tiny, less than one centimeter in diameter, firm in consistency, raised above skin level, and pink or reddish-brown in color. The texture of this mole can be either smooth or scaly.