My 2-yr-old bit his tongue and he now has a couple millimeter wide, half circle, flap on the side. If there is no bleeding, does he need stitches?

Doubt it. The mouth mucous has antibacterial qualities that reduce infection risk, and most of these heal with no treatment.Had he sliced a deep hole with a big flap of tongue moving around,an oral surgeon or ENT might work on it.What you describe should heal if left alone.