Socks?

[rerant]

Even better, the kid's wearing the socks, and gives co-worker some nasty food thing because the kid stepped in something.

Like their own pee in the ball pit? Yeah, that's why when I'm asked to cover a shift in Smaland I quickly decline. Even though one main rule is the kids need to be potty trained, they so often pee all over things.
And the parent's response? Usually it's something along the lines of, "Oh yeah, I forgot to mention that he/she does that sometimes."
That's cool. Here's your bucket of soapy water and disinfectant to go clean the soiled remains of our "daycare" facility.