Physical Properties of water: Ice

In our group I did not do my topic on ice but I was fascinated by Jesse's information on it. So I did some research on it because Anne sais we would have a quiz on all the presentations. Anyways I did more extensive research on that and found the the differences in densities between ice and water. One way to see this is to place ice on top a glass of water. The ice will float meaning ice must be denser than water. Most solids would penetrate the surface because they are denser than water and sink to the bottom. Water has a strong surface tension making it difficult for objects to penetrate its surface. I always thought ice was denser than water. I wonder why a solid such as ice is denser than a liquid such as water. Here is a good website that has 4 explanations for why ice floats on water. http://www.newton.dep.anl.gov/askasci/phy00/phy00136.htm. According to this website matter that displaces a liquids surface has to rise equal to the matter that was displaced. So that would explain why a solid placed on a liquid makes the liquid rise.