Where I live it doesn't get very cold, so I try to take off my shoes before I enter the house, but if my hands are full I often cheat and take them off after I get inside. When it gets cold I wear socks or fuzzy slippers.
I just saw a news story on TV where they took samples from the bottoms of people's shoes and examined it in a lab, they found E. coli, staph and strep. Guess I should really tell my kid to throw away those chicken nuggets that fall on the floor instead of eating them.