Giraffes sleep very little.
Why it is true
In the wild, they sleep 30 minutes to 2 hours a day in short naps to stay vigilant against predators.
Source: Wildlife Research
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.