I have a few tiny bumps behind each of my ears. they aren't painful and dont itch but they've been there for at least a few days. what are they?

Lymph node.: Those sounds like post-auricular lymph nodes, which could enlarge in response to an ear or sinus infection. If they eventually go away completely, say in two to four weeks, then there's no cause for concern, especially if you have symptoms of said infections. If they do not go away, you may want to have them looked at - sometimes we need to take these out for definitive diagnosis if they linger.