Bats and Stainless Steel Earrings: The Surprising Corrosion Connection You’d never guess bats could harm your stainless steel earrings—but these nocturnal creatures can trigger unexpected metal damage, and it all boils down to their biology, not just direct contact. What seems like a random pairing of wildlife and jewelry is actually a small, science-driven issue that’s easy to overlook. The corrosion starts with bat waste, not the bats themselves. Bats excrete a waste product called guano, which is high in uric acid. This acid is far stronger than the organic acids from leaves or flowers—even tiny, dried guano particles (that might stick to earrings stored near windows, porches, or attic spaces where bats roost) can slowly eat away at stainless steel. Moisture makes it worse: if the earrings are exposed to humidity or occasional rain, the guano’s acid dissolves slightly, creating a mild solution that breaks down the metal’s protective layer faster. The damage shows up in specific ways. At first, you might see a faint, chalky white film on the earrings—this is the acid reacting with the steel’s surface. Over time, that film turns into dark, spotty discoloration, and eventually, tiny pits can form. Unlike leaf corrosion, which often progresses slowly, guano acid can cause visible damage in weeks if the earrings stay in a bat-accessible area (like a windowsill where bats perch at dusk). Protecting your earrings is straightforward. First, keep them stored indoors in sealed containers—avoid leaving them on outdoor tables or open windowsills where guano can land. Second, if you suspect contact with bat waste, clean the earrings immediately: use a soft cloth dipped in a mild baking soda solution (to neutralize the acid), then rinse and dry thoroughly. Finally, check areas where you store jewelry for signs of bat activity (like small droppings) and seal any gaps to keep bats out. With these steps, you can keep your stainless steel earrings safe from this unusual threat.