6 yr f healthy no other symptoms found a semi hard pea size lymph node on back of neck. Doesn't hurt what to do?

Yes. There are thousands of lymph node located around the body.Many in the neck, head, behind the ear are prominent in kids as they are not buried in tissue . At rest these are often 1/4 inch in diameter and may grow to marble sized when reacting to a stimulus. Bug bites, or viral infections can increase their size to 1 cm or more.Most will shrink down to pre-stimulated size over 3-4 wks.