It is supposed to happen, not a bug. Player 1 cannot leave the area of the 'anthills' and regains control of Jack and the supply cart once he defeats the other 'ant states'. Not to get stuck the 'anthill' creates units until you won, which includes the destruction of the enemy anthills, you get stronger ants, militias for kills. In addition, the constant flow of units out of the 'anthill' shows the theme, anthill. There are about 6000 different ant species with organized states from under hundred to some million units.