Scary find in my washroom!

I had a horrible scare when I saw a centipede in my washroom after my shower yesterday afternoon!!!  I was trying to fill water into Alvan's bathtub and spotted a centipede at the corner!! I got a shock and started splashing it with water, but it was still trying 'swim' away... And suddenly realized, I should use hot water!!! And it died after 2 splashes of hot water!!! Whew... But I seriously got no idea how it went into my washroom!!!!