How do Worms Breathe?

A worm has no lungs or a nose so just how does a worm breathe? A worm has mucus on its skin that allows oxygen to dissolve so a worm actually breathes through its skin. The oxygen enters the worm’s circulatory system where the heart pumps the oxygen throughout the body. A worm’s skin must stay moist so it can absorb the oxygen because if it ever dries out the worm will die.