BT NOW is a water-based, biological insecticide that utilizes a novel strain of bacteria, Bacillus thuringiensis ssp. kurstaki (Btk), to offer targeted control of the caterpillars of certain moths and butterflies on a wide variety of crops. Ingestion of BT NOW paralyzes the insect's digestive system within hours, halting further crop damage potential. The affected larvae die within 2-5 days.