Mussels filter up to 40 liters of water per day, cleaning polluted lakes and reservoirs similarly to chemical engineers. Spiders produce different types of silk through an acid-based chemical process in their bodies. Canaries were historically used as early warning systems for detecting toxic gases in mines. Honeybees chemically process nectar into honey through enzymes that convert sugars and produce hydrogen peroxide as a preservative. Electric eels produce large electric charges through thousands of battery-like cells to stun prey or defend themselves.