They contaminate the stored produce by urinating on the produce and through their droppings (faecal material) which get mixed with the stored grain, rendering the produce unusable
amayipitsa zomwe zasungidwa pokodza pa zokolola komanso kudzera mu ndowe zawo (zinthu zakunja) zomwe zimakasakanizidwa ndi tirigu wosungidwa, zomwe zimaangitsa kuti zokololazo zisagwiritsidwe ntchito