Children receive nourishment through the oral cavity but also receive pleasure from the mouth. The sexual pleasure of the children is to receive into the body their object-choice. Their foremost defense mechanism is when they start teething where they enter the second phase of Oral Stage called Oral Sadistic Stage where they respond through cooing, biting, closing their mouth, etc. As children grow older, Oral continues to be an erogenous zone but satisfies it through various ways.