What has happened it they have hatched because you've seen the tail, she's then picked them up in her mouth and placed them in a pit. To the naked eye they prove difficult to see, but a good ehye will let you see them.
In about 4-7 days they'll be swimming. In 2-3 weeks there'll be 200-300 more eggs. In 3 months there'll be nough to supply a mid sized town. Even in a year, they'll still crank out eggs at an unbelievable rate.