Ducks Grow Natural Built-In Sunglasses
Ducks have a special oil-producing gland that coats their feathers to block harsh ultraviolet rays while they swim on sunny water. This oil not only keeps their feathers dry but also helps them avoid eye damage from reflected sunlight. Researchers discovered that the amount of oil changes with the seasons, giving ducks stronger protection during bright summer months.
💡 Fun detail:
If you look closely at a duck’s eye you might notice a tiny drop of this protective oil that acts like built-in sunglasses!
Source: National Geographic