Okay, I looked up the whole breathing situation for bees, in case anyone else is curious: “Insect Respiratory System
Air enters the respiratory systems of insects through a series of external openings called spiracles. These external openings, which act as muscular valves in some insects, lead to the internal respiratory system, a densely networked array of tubes called tracheae.
To simplify the insect respiratory system, it acts like a sponge. The sponge has small holes that let water into the sponge moistening the sponge. Similarly, the spiracle openings allow air into the interior tracheal system bathing the insect's tissues with oxygen. Carbon dioxide, a metabolic waste, exits the body through the spiracles.”
Back before the meteor hit 65M years ago, there was much more oxygen present in the atmosphere. Insects could grow to gargantuan sizes, like the Bolsover dragonfly, because oxygen could diffuse father into their spiracles. If you want some crazy-interesting science reading, check this out: http://nick-lane.net/chapters/oxygen-chapter-5-bolsover-dragonfly/
Air enters the respiratory systems of insects through a series of external openings called spiracles. These external openings, which act as muscular valves in some insects, lead to the internal respiratory system, a densely networked array of tubes called tracheae.
To simplify the insect respiratory system, it acts like a sponge. The sponge has small holes that let water into the sponge moistening the sponge. Similarly, the spiracle openings allow air into the interior tracheal system bathing the insect's tissues with oxygen. Carbon dioxide, a metabolic waste, exits the body through the spiracles.”