The girls have this habit when they play in the sandpit, they like to go barefoot.
Doesn't matter what time of year or how cold it is, they like to get their feet in the sand.
I've given up trying to fight it and just smile as I see them running across the garden carrying their wellies. Trying to keep them from walking it all round the house is another matter, we make them dunk their feet into a bowl of water before they're aloud in!
Simple childhood pleasures