didyouwonder.com

YMNd TIL that igloos can retain a temperature of 60° F during -50° weather. Fire inside melts the inner layer of ice, and the cold outside refreezes it, adding a layer of insulation.
gdmD TIL humans can have black irises, and red is the most rare of eye colors.
ADE7 TIL that the Danish King Harald Blatand ate so many blueberries that his teeth stained blue. “Bluetooth” is named after him because of his ability to unite warring Scandinavian factions, just as Bluetooth unites wireless devices. The Bluetooth logo is also a combination of the Kings Runic initials.