When I read this, I thought to myself, I am so glad I was not the only one. I had this same problem until my daughter started preschool. She was four when she started and I discussed with her preschool teacher that we had not ventured to this issue yet with her; I wanted to make sure her bottom was clean and I thought kids this age could not do this. Anyway, the preschool teacher began to tell me that they are old enough and peer pressure is a good thing in this area. So her first week of preschool I was very nervous to say the least. Within a week or two she was cleaning her own bottom, all by herself and doing an excellent job. So to answer your question, yes, they are old enough to know and proceed to clean thier own bottoms. Hope this helps.