The dangerous things you should let your children do include whittling, throwing a spear, playing with fire, climbing a tree, cooking with weird ingredients and taking equipment apart. Danger has been defined down. A not-very-brave girl, I did most of these things. (I never threw a spear, but I made bows and arrows out of garden stakes and used them in our games of Pony Express.)
However, I’ve never licked a nine-volt battery.