Most birds migrate, meaning they travel to cool places during the summer, then back to warmer places to spend the winter. One red knot, known as B95, has flown 20,000 miles a year since 1995. He flies way up to the Arctic from the tip of South America, with a stop at Delaware Bay to munch on horseshoe crab eggs. By now he's flown far enough to have traveled all the way to the moon (240,000 miles) and back. So bird watchers have named him Moonbird - a much cooler nickname than B95!