once water starts dripping, it begins to freeze into a certain side. it will melt and freeze over and begin to create icicles. as winter gets longer and temperatures stay in the freezing and sunlight is present, water will just melt and drip alongside the icicle causing them to get longer and sharper. the reason why icicles are pointy is because the water drips in a downward motion. icicles can range from millimeters to feet in length.