You'll never see a rainbow at high noon. They only appear when the sun sits below about 42° — so mornings and late afternoons.
Only female mosquitoes bite — they need the protein in blood to develop their eggs. Males just feed on flower nectar.
Australia's Nullarbor Plain stretches about 200,000 km² without a single tree — its Latin name literally means 'no trees.'
Mark Twain was born in 1835 when Halley's Comet appeared, and died in 1910 the next time it returned — exactly as he'd predicted.