British spies used semen as invisible ink during WWI British spies were experimenting with all kinds of invisible inks during the first World War. In 1915, one spy was quite excited to discover a rather

DID YOU KNOW…

During WWII, the British used semen as invisible ink because it couldn’t be detected with iodine, unlike other inks.

#InvisibleInk #WWI #MI6 #Spycraft #Semen #SemenInk #Spunk #Spink #StinkyLetters #FunWithHashtags

gizmodo.com/british-spie...