Dispelling the myth that raccoons wash their food
The short answer for why raccoons wash their food is, they don't. Surprised? I sure was! You, like me, have probably always heard about how raccoons like to wash off their meal before they dine. But after noticing that raccoons in captivity go through the same motions with their food regardless of whether or not there is water around, researchers questioned if this was actually a habit based on cleanliness. What they discovered is that the propensity for raccoons to dip food in water actually has little to do with washing it. Instead, it's all about making their paws more sensitive to touch, so they can take in more information -- such as shape and texture -- about what they're about to eat.
Here is how How Stuff Works explains it: "Raccoons actually have the same nerve grouping on the hairless parts of their forepaws as primates have, including humans, making them very sensitive to touch ... In a study examining the slowly adapting nerves in the forepaws of 136 raccoons, researchers found that wetting the skin increases the nerve responsiveness. Think about what happens when you look through a pair of sunglasses and then quickly take them off. When you remove them, your optical nerve responsiveness will likely increase because more light is flooding into your retinas to illuminate what you're looking at. Likewise, when raccoons perform their dunking ritual, the water on their paws could excite the nerves in their forepaws. That, in turn, gives them a more vivid tactile experience and provides precise information about what they're about to eat. This is a beneficial trait since the raccoon's vision isn't its keenest sense."
In watching raccoons feeding at the edge of a pond, you'll notice they often look up while moving their forepaws around to search for food, tap-tap-tapping along until they find something that feels like lunch. They're using their hands to see and find food, rather than their eyes. Rolling their catch around in their paws lets them know just what they're about to eat. Same goes for when there is no water around at all. While the action looks like washing, it's more about getting a good enough grip on their catch and figuring out the best way to get their meal into their mouth.
If you're worried about this ruining your perception of raccoons as cute little bandits that steal food from trash bins and backyards then wash it before eating, don't worry -- they're still cute little bandits that steal food from trash bins and backyards.