I am new so show mercy on me as I am not familiar with how formal this
newsgroup may or may not be! :-)

MUAHAHAHAHAHAHAHAHA!

I have some adorable little hen & chicks mix & a few days after potting
them
they seemed to burst open & multiply. Wonderful! Except I began to notice
teeny tiny little black "things" moving inside the inner most crown.
Horror!
My 14 year old son said to put some lady bugs on them. I did. I put 3. One
of the lady bugs has stayed for 3 days. The other two abandoned me. First
,did we do the right thing? Next WHAT are the teeny tiny little black
things? And finally why did the other lady bugs leave & will they return?
Any kind suggestions will be gladly appreciated.

Well, your son was probably correct -- assuming the little buggers are
aphids, ladybugs will do wonders. Ladybugs are great as they're carnivorous
little stinkers -- they love the taste of small insects like aphids.

As for why they didn't stay -- could be a couple of things. First and
foremost, they need food so they will not hang around if there's no food.
You might want to try putting a net around the plant before putting the
ladybugs into it (i.e., one they cannot get out of) or you might just want
to buy some ladybugs and put them and the plant outdoors for a bit.

ps. the lady bugs are from our home.

From inside your home or outside?

James