It is normal for babies to suck on thumbs, fingers or pacifiers (dummies)
Over time, they should lose interest
Prolonged sucking on fingers/thumb can cause changes in tooth positioning and alter the upper arch /upper airway.
Thumb sucking is harder to break than pacifier use. You can take away a dummy but a thumb is forever!!!
Dr Charmaine Hall loves to use positive reinforcement to help patients know that they are safe, loved, and that they are doing great when the thumb isn’t in the mouth. Some children may benefit from using a thumb blocker – that reminds the child to not use their thumb.