What is one thing you caught your child doing that you wish you had never seen?

When my baby was one and a half year old, she had started crawling. And one day, I was doing something when I suddenly noticed that she was trying to kind of spit something out of her mouth or something. I quickly went and opened her mouth and saw a cockroach in her mouth. While crawling, she got hold of a cockroach, and had put it in her mouth. :)