Adults passengers traveling domestically are required to show photo identification in the form a valid passport or state approved photo identification card. According to the Transportation Security Administration's website, adults without identification may still enter airport boarding areas if they are cooperative with security screening personnel and possibly subject themselves to enhanced security screening procedures such as body and baggage checks.
According to iFly's online airport guide, children flying unaccompanied without an adult need to have the adult dropping them off at the airport as well the adult picking them up at their destination show a valid photo identification card to airline personnel. Children traveling with an adult may not be required to show photo identification but may be required to show proof of age through a birth certificate.
Checked bags should be marked with passenger identification and contact information. Pets that are checked in as cargo should be wearing a collar with the owner's identification and contact information.
