Originally Posted by Coidzor
Creep requires structures to promulgate it though, and so the zerg would need to go around the lines or manage to have the orks completely ignore their structures.
I guess really it depends upon the savviness of whatever is controlling the zerg on Tarsonis.
I guess this is the era before brood mothers but after Zerg Queens started getting more autonomy/control?
I guess their 'stealth' might be just being big blobs of creep and hard to distinguish from all the rest of the creep around them...