What are signs that the baby has wind and need a burp?

Signs include the following: baby curls his tongue upwards.

• baby seems to want to scream, but he makes no sound.
• baby gasps or pants.
• baby makes high-pitched wailing shrills, or ‘eh’ sounds.  
• baby may hold his breath between screams.
• baby makes screwed-up faces, resembling a cross between smiling and pain, maybe rolling his eyes.
• baby’s body tenses or becomes rigid.
• baby’s arms may slightly shake or make jerky movements.
• baby may squirm on his bottom or pull his legs up to his chest.