The term 'Adult Nits' refers to LICE, which are small parasitic insects that feed on the blood of humans and other animals. They can be found in the hair and scalp of adults, and are usually spread through close contact with an infected person. Adult nits are the eggs of LICE, which are laid on the hair shafts and hatch into nymphs. Treatment for adult nits involves using a special shampoo or lotion to kill the LICE and their eggs.