Scientists have discovered an extreme case of regeneration. Some sea slugs can regrow hearts and whole new bodies after having their heads cut off! It is being called a “wonder of nature” and was recently reported in Current Biology. This discovery could help scientists better understand how to regenerate, or regrow, human tissue in the future. Biology researcher Sayaka Mitoh said she loves studying Japanese sea slugs because they are small, cute, and strange. They can even briefly photosynthesize like a plant drawing food from the sun.