Do you have floor drains that are smelly, running slow or serving as a breeding ground for fruit flies? Then put the DRAIN SHARK CAGE Bacteria Blocks on the attack. This unique system features Bti bacteria that will battle the FOG in the drain and work to eliminate the fruit flies as it degrades their feeding and breeding grounds. It’s easy-to-use, Earth Smart® Certified and each bacteria feeding into the cage will treat the drain for a full month.