Guano – the Natural Remedy for Infertile Deficie... Birds are generally thought of as creatures of air with little to do on land except picking food and dropping excreta. But eco-conscious communities are now turning to the excrement of these airy creatures as the most valuable organic fertilizer, known as Guano in common terms. While a number of different bird excreta are now considered as guano, that of bats, seals, and seabirds particularly define the classic organic...