Float, not sink!

Today, I was drinking sweet tea with ice, when I became aware that all the ice cubes were floating.  The reason for this is because, unlike other substances, water has less density when it freezes than the density it has in its liquid state. Water is different from the other substances because of hydrogen bonds. Since ice is less dense (also lighter than water), the heavier water will move towards the bottom of the container while the lighter ice floats to the top.  Fun fact: this is why fish are able to survive in frozen lakes or ponds during the winter:  lakes and rivers freeze from top to bottom; the ice floats while there is still water in the bottom of the lake, allowing the fish to live and survive there.