Insects breathe not through their mouths. They inhale oxygen by exhaling carbon dioxide through a hole called spiracles in their exoseletons. These holes usually line up thoraxes in the insect's stomach. Surprisingly, the insect respiratory system is also unrelated to the animal or human circulatory system. Where gas exchanges the lungs with blood flow. Instead, Insects have cardiovascular tissue such as a tube called Trachea System. That gives oxygen and removes carbon dioxide from every cell in the animal's body. Speaking of the circulatory system, The way insects are different from humans. Insects have an open circulatory system where their blood called "hemolymph" organs. The liver of the insect is a segmented tub and the cubicle runs along the animal's back. Contract this tub to send hemolymph to the head. From there it will return to all body tissues. hemolymph is usually greenish or yellowish.
