There are houses where you take your shoes off and houses where you leave your shoes on. I tend to encourage people to leave their shoes on in my home because I steer away from things like mopping and such, but every now and again I am reminded of another reason to encourage my guests to leave their shoes on.
I am married to machinist. Sometimes I find things like this on the floor:
Thankfully, no one has ever found this sort of thing wedged in a toe.