How do insects Breathe?
Insects do not breathe the same way that we do. Oxygen travels to insect tissues through tiny openings in the body walls called spiracles, and then through tiny blind-ended, air-filled tubes called tracheae. For a given tube diameter and temperature, gas molecules diffuse over distance at a rate proportional to the source concentration. In other words, air that contains more oxygen allows the minimum amount needed for metabolism to reach farther into the insect’s tracheae. Some insects can increase oxygen delivery by a mechanical pumping action of their bodies. Humans and other vertebrates are less likely to be affected by atmospheric oxygen concentration, since oxygen is delivered by blood that is pumped thrir oxygen from the water. How? They have sets of thin flat lacy things called gills instead of lungs! They suck water into their mouths and then push it out through these gills which are located on either side of their mouth. As the water flows out, their gills pick up the oxygen in water so they can breath. That's pretty clever, eh? But, then, listen ... fish can't sunbathe the way you humans can.
http://askabiologist.asu.edu/how-insects-breathe
Insects do not breathe the same way that we do. Oxygen travels to insect tissues through tiny openings in the body walls called spiracles, and then through tiny blind-ended, air-filled tubes called tracheae. For a given tube diameter and temperature, gas molecules diffuse over distance at a rate proportional to the source concentration. In other words, air that contains more oxygen allows the minimum amount needed for metabolism to reach farther into the insect’s tracheae. Some insects can increase oxygen delivery by a mechanical pumping action of their bodies. Humans and other vertebrates are less likely to be affected by atmospheric oxygen concentration, since oxygen is delivered by blood that is pumped thrir oxygen from the water. How? They have sets of thin flat lacy things called gills instead of lungs! They suck water into their mouths and then push it out through these gills which are located on either side of their mouth. As the water flows out, their gills pick up the oxygen in water so they can breath. That's pretty clever, eh? But, then, listen ... fish can't sunbathe the way you humans can.
http://askabiologist.asu.edu/how-insects-breathe