Animal migrations are astounding in lots of ways. But even so, the latest research on the migrations of small birds is unbelievable. Bar-tailed godwits fly 7,100 miles (11,400 km) across the Pacific without a stop to rest or feed - and in nine days. Arctic terns, meanwhile, make stops along the way, but can fly as much as 50,000 miles (80,000 km) a year. Makes us humans seem as mobile as limpets by comparison!