Despite their dirty reputations, some wild boar carefully wash their food before pigging out.
Researchers at University College London and Basel Zoo in Switzerland made their discovery after a zoo employee spotted several wild boar bringing dirty apple chunks to a stream and sloshing them around before eating them.
Follow-up experiments confirmed the pigs can tell when their food was dirty and that they can delay gratification by washing their food, rather than chowing down immediately.
Pigs are intelligent animals known for their ability to adapt to new environments. So one might expect them to be capable of discriminating clean food from dirty food and delaying gratification to wash food items. Yet this is the first reported observation of pigs washing their food. The researchers recently reported their results in Animal Cognition.
The discovery could help change the way some people see pigs. Despite the animals' reputation for greed and uncleanliness, they're actually thoughtful and fastidious animals.