Wendy, how is the ferocious feral kitten coming? Your story reminded me
of a black kitten who inspired the term, "pink hisses." Though in your
case (and hers, as well), the hisses were more than just noives.

What you might try for Red Tongue is isolating him/her in cage with you as
the only contact. Physical contact is very important to kittens; you just
may start to look pretty good to this kitten after a day or two "in stir."

Separating the fractious kitten from its siblings may well help settle the
other kittens down as well.

Sharon Talbert
Friends of Campus Cats