Thumper tower

A highly specialised support tower with a sole function. Thumper towers drive a central unit up and down apparently creating shockwaves that are either extremely uncomfortable or heavily damaging to underground burrowers. In any case the burrowers do not burrow within the range of a thumper tower and so are left vulnerable to your' entire ground offensive tower force.

Thumper towers need research for both the blocking and chaos towers first and thumper research is a little pricey(250 resources).