Wheat

Wheat can be grown to produce grain.

Planting
To grow wheat, the first step is to place grain in some earth. It must be placed on a earth block itself, not on the empty space above the block. The earth must have no tree or bush growing on it and neither can have roots.

Wheat does not need to receive sun to grow; because of this it can be safely grown and harvested underground or inside of a shelter.

It does not need watering either, despite the game description.

No tech is required to harvest wheat from nature or to plant it. But to extract grains from the wheat ears, the farming tech is needed.

Rats and crops
Rats' nests will drop 5 or 10 wheat ears when destroyed, no matter if the rats have spoiled the crops or not.