Gold headed sleeper goby does not eat!!!!! 10 points to best answer?

i have a mated pair i got them 3 days ago ... each time i put frozen food or pellet food they run and hide in their cave while the rest of my fish eat... and when the foods gone they go out and sift the sand ... so what should i do should i breed pods to feed them ??? or what cause i have a refugium but no pods yet i need to add them but maybe theyll eat those.. WHAT should i do??