Why do volcnos spit lava?

Volcanoes erupt and spit lava due to the buildup of pressure from molten rock, or magma, trapped beneath the Earth's surface. When this pressure exceeds the strength of the surrounding rock, it causes the magma to rise and escape through fissures or vents. As the magma reaches the surface, it can erupt explosively or flow out as lava, depending on its composition and gas content. The release of gases and the movement of magma are key factors in volcanic eruptions.