Usually, solids have a higher density than that of liquids. But Ice floats on water.
Ice is generally regarded as a solid-state of matter. So apparently it must float on water but it does not because it comprises of cage-like structures and has a large number of empty spaces between the particles. The spaces present in ice are larger as compared to the spaces present in water molecules. So ice has a smaller density as compared to water. So ice being a solid floats on water.