Faith and Certitude!

The Mole people have laws..

Yes, even the Mole people have laws.
Wherever you have a community there will be laws to govern it.
Space is limited underground, nothing is left to waste.
Cannibalism is a common practice.
Nonproductive citizens are eaten.

But, promiscuity is encouraged.
There is a need for fresh breeders, which are captured, surface dwellers.
Clothing is minimal in the warm dank caverns.
Sewage was be managed quickly to prevent gas build-up.
Some sewage is recycled into fertilizer for underground mushroom farms.

Any dispute is settled legally in a Mole court.
Many disputes are bartered others are decided by the cast of the dice.
The highest role of the dice wins.