Wormery problems

Hi there, I have a wormery in the back garden, about 3ft square wooden box, filled with a 1/2 and half mix of horse poo and soil. The dendra's I have put in love it, and for about a month they have thrived.
But the wormery now resembles and ant pit. The little buggers have made a damn great nest in it.
My questions are, will they harm the worms and how can I get rid of them?

Cheers, Andy Doughty

Andy - sprinkle ant powder on the ant path too and from your wormery. The ants will carry it back to their nest and they will die. Then the worms will eat them but will not be affected by the ant powder.

or chalk dust