Would your overtired baby sometimes refuse to nurse to sleep and just cry? What do you do?

We used to feed to sleep all the time, baby is 6 months exactly. Since yesterday he cries before naps and bedtime, when I try to latch, he bites me.
What could this mean? He doesn't bite when he's actually hungry, he eats just fine. So I end up just rocking him. Does anyone here have the same experience?