Archipelago Bat Guano - 2 Pounds (Earth-friendly Packaging) Archipelago Bat Guano Phosphate is very effective in promoting exceptional fruit and flower development. And because the guano is fossilized, it has no foul odor. Archipelago bat guano is a socially and environmentally responsible company that provides home gardeners with what we believe is the best phosphate, calcium, and micronutrient fertilizer Archipelago Bat Guano Phosphate is 100% natural and organic, and it is OMRI listed for use in the production of organic food and fiber.