How do worms exchange gases?

Answer 1

Earthworms need oxygen, just like other living creatures. They don't have lungs. They breath through their skin. Like frog breaths in water. Their respiration process occur through diffusion (transfer of atoms from higher to lower concentration).

Answer 2

Worms do not theoretically breath as they have no lungs. However, the skin remains moist so as to absorb oxygen from the air through tiny pores in their skin.