Another reason for tongue clicking is a short lingual frenulum (tongue-tie).
The frenulum snaps the tongue away from the breast at the end of each
peristaltic wave, mom will often have a blister on the tip of her nipple from
friction if this is the case.  Also kids with low muscle tone might "fix" the
tongue to compensate.  Low tone kids fall off the breast all the time.  There
was lots of discussion on this issue a few weeks ago, access the digests.  One
tip, have mom bring baby to breast with the lower jaw leading to increase
tongue-breast contact.
Catherine Watson Genna, IBCLC  NYC  [log in to unmask]