The respiratory system of beetles operates by inhaling Oxygen and exhaling Carbon Dioxide. Some beetles that swim can even bring an “air-bubble” down with them in order to breathe under water!
Like most insects, beetles inhale oxygen and exhale carbon dioxide via a tracheal system. Air enters the body through spiracles, and circulates within the haemocoel in a system of tracheae and tracheoles, through the walls of which the relevant gases can diffuse appropriately.[6]