My grandmother turns 100 in January and over the weekend my sister, aunts, uncles and cousins did some massive cleaning of her home in Rhode Island. While cleaning out a drawer upstairs one cousin discovered an apparent souvenir from my late grandfather's World War II service: a hand grenade. My aunts said it was real and they remembered playing with it (?!) in their childhood. The police were called, and the bomb squad showed up too, and the device was taken away for detonation at Fort Devens in Massachusetts.
If any of you vets or weapons experts can identify and explain what this is in a more historical context, please do so in the comments section.
Meanwhile, this might offer some perspective to parents who obsess about bike helmets and BB guns.