Aquariumgirl I'd have to say those are baby sun corals! Ive owned a few sun corals but ive never had that happen.However i've seen it happen in many ppl's tanks,usually they do that at night so u would never see it.
Once they get big enough try feeding them?
Theres a good thread on RC that shows an acan reproducing,in the lps forum
BTW if they are doing that in your tank,your definetly doing something wright!