Penguin sweaters, also known as penguin jumpers, are sweaters which are knitted for penguins that have been caught in oil slicks. When an oil spill affects penguins, they are dressed in knitted sweaters to stop them preening their feathers and to keep them warm, since the spilled oil destroys their natural oils. This also prevents them from poisoning themselves by ingesting the oil. The sweaters are removed and discarded as soon as the penguins can be washed. The original project has been completed, but the knitting pattern is still available on-line, as subsequent oil spills make it necessary. The extra sweaters are kept on behalf of the Wildlife Rescue Team.