Minecraft wiki entry for Defense, associated text: Torches are by far the most commonly used light source for this purpose. Moats of lava, glowstone, jack o'lanterns, sea lantern and lantern can also be used, though the scarcity of glowstone and sea lantern in singleplayer is a limiting factor, and pumpkins, which are used to make jack-o-lanterns, are rather hard to find. Lava is sometimes problematic to use because it ignites flammable materials that are within four blocks.