Here's why:

* Formation: Stalactites are formed when water containing dissolved minerals (like calcium carbonate) drips from the ceiling of a cave. As the water evaporates, the minerals are left behind, gradually building up over time to form the icicle-like structure of a stalactite.

* Direction of Water Flow: The water is flowing downwards from the ceiling, so the mineral deposits are concentrated at the point where the water drips, creating the stalactite hanging from the ceiling.

Fun Fact: Stalactites are often paired with stalagmites, which grow upwards from the floor of the cave. Stalagmites are formed by the mineral-rich water dripping from the stalactite and hitting the floor.