Chocolate effects a dogs heart and nervous system, a few ounces enough to kill a small sized dog. http://www.FactLib.com/1662/ A fetus develops fingerprints at eighteen weeks! http://www.FactLib.com/176/ The Chinese national anthem is called "the march of volunteers." http://www.FactLib.com/3482/ While known as a painter, sculptor, architect, and engineer, Leonard da Vinci was the first to record that the number of rings in the cross section of a tree trunk revealed its age. He also discovered that the width between the rings indicated the annual moisture. http://www.FactLib.com/2678/ Males lions can sleep for up to 20 hours a day. http://www.FactLib.com/1698/