An ear infection is a bacterial infection of the middle ear, the space behind the eardrum. It usually develops several days or more into a viral cold. The cold virus causes fluid to collect in the middle ear and then the fluid becomes infected with bacteria. Symptoms typically include fussiness, poor sleep, decreased appetite, and sometimes fever or decreased hearing. If your child is old enough to talk, he or she is likely to complain of ear pain as well. Many young kids with an ear infection will pull the ears, though this is common with colds too and is not a reliable indication of an ear infection.