A good way to make children more defensible, is to teach them where they can be touched and by who. The Underwear Rule by The Council of Europe is an effective way to teach it to children. They have made a story about Kiko and The Hand. The Hand asks where Kiko can be touched. For example the face, the hands... are okay. When The Hand asks about where the underwear is, Kiko gets mad. He can't be touched there, by nobody. 

- Watch the children's non verbal language

An effective and important way to protect children against sexual abuse is to teach them and give them the power and ability to say 'no'.