The Arctic tern migrates from the North Pole to the South Pole every year.
Why it is true
The Arctic tern migrates from the North Pole to the South Pole every year, a journey of about 70,000 kilometres. It spends the summer in the Arctic and the winter in Antarctica, making it the animal with the longest known migration.
Source: Audubon Society
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.