To bathe a pet hedgehog, you should fill a shallow container with warm water that reaches their belly but not higher, as hedgehogs are not good swimmers. You can use a small amount of gentle, fragrance-free pet shampoo. Gently place your hedgehog in the water and use your hands to carefully wash their quills, belly, and feet. Be sure to rinse them thoroughly and dry them off completely with a towel or a low-heat hair dryer. It's important to keep the bathing process quick and gentle to minimize stress on your pet hedgehog.