A diaper changing room:
A room which is used to change diapers, or that has other forms of excrement in it, should have the Mezuzah of its doorpost covered.
 Michaber 286/5; Shach 289/9
Other opinions: Some Poskim rule one should not place Mezuzahs in such a room. [Bach, brought in Shach 286/9] The Shach ibid concludes that one should place a Mezuzah in the room and cover it.