We also remove our shoes when we are at Tres Mariposas because we have to respect children's work as well as not bring dirt into the area where children work. This is because in Montessori schools children typically "work" on the rugs when completing lessons for the day. This "rule" of removing shoes is also very important because the area in which the school is located and where most children live has dirt roads. These dirt roads also become very muddy in rainy weather causing messy shoes that could ruin children's work and their area of play.
P.S. I have been enjoying being able to comfortably walk around without shoes!
-Jasmine, the shoe-less walker