Several comments about my question for examples of superstitious behavior
totally ignored my definition of it.  I am not talking about superstitious
beliefs on the part of the mother.  I am talking about behaviors that are
accidentally reinforced in the baby.  This is a behavioral psychology
definition, not the common usage of believing black cats bring bad luck
etc. Here is what I said:

"I am collecting information on superstitious behavior in breastfeeding
infants.  In behavioral psychology, superstitious behavior is a behavior
that is reinforced accidentally.  In other words, if a rat pushing a lever
scratches his ear and then the food pellet comes, it may associate the food
pellet with scratching his ear, rather than pushing the lever and continue
trying to get food by scratching his ear.  If food occassionally comes
after he scratches his ear, that behavior will become a superstitious
behavior that is hard to extinguish even though there is really no
connection to receiving food.

Two examples in breastfeeding babies :

A baby boy that continually popped on and off the breast, continuing this
behavior all through his breastfeeding career (through toddlerhood).
 Probably got accidentally reinforced early on when let-down occurred right
after he latched back on.

A baby girl that "hummed" until the milk let down.

Curious whether other people have had similar situations with behaviors
otherwise unexplainable."