Guano is actually an amazing fertilizer, as it is high in potassium nitrate, which plants love. Consider placing the BatBnB above a low-traffic, non-edible garden bed and the guano will help the plants grow big and strong. Be mindful however, that if too much guano is accumulated it could burn the plant like too much of any fertilizer, too much nitrogen.  Interestingly enough, the potassium nitrate can also be extracted and used in gunpowder and explosives; guano was an important resource for that purpose during the American Civil War. Bat guano has also been found to preserve fossils.