In habitats across the planet, animals periodically drop everything to walk, fly or swim to a new locale—and lightweight tracking technology has given biologists their best-ever understanding of these seasonal treks. Wildlife such as whales and geese learn migration routes by following their parents and other older counterparts. Others, including small songbirds, inherit the distance and direction of their migration deep within their genetic code. And some animals use a combination of genetics and culture to guide their migration.