Icicle also known as ice stalagmites are formed if temperatures are below freezing temperature, the water will collect on the floor into stalagmites. Deposition may also occur directly from the freezing of water vapor. Upside-down ice icicle are formed as the ice slowly freezes in from the edges, until just a small hole is left unfrozen in the surface. At the same time, while the surface is freezing, more ice starts to form around the sides. Since ice expands as it freezes, the ice freezing below the surface starts to push water up through the hole in the surface ice.