I wondered why it hadn't showed its face, it just hides now. Either he's made some little footballs to play with and doesn't need to eat or show his face any more or ...
Felt ill looking at these when I cleaned the tank, it's only a couple months old! Blergh
every 30 days or so if you have a pair... they take 3-5 days to hatch if they are fertile... If you have no male, they aren't fertile and wont hatch...