From what scouting we have managed to muster, we believe that the foe south of the gnolls is an insect-like race.  Frankly, it is irrelevant whether or not if they're sentient.  If they are driving the gnolls to frenzy against us, then they are as big of a threat - if not more - than the gnolls.$B$BDrive deep into where these Zukk'ash insects dwell; it is known as the Writhing Deep.  Thin their numbers and report back to me what you find, bringing back their carapaces as evidence of your handiwork.