Cockroaches Release Gas
Cockroaches release gas when they eat rotting food. These gasses are non-odorous and non-toxic. These emissions are the result of bacteria that colonize the cockroach gut. These fecal emissions are often undetectable by humans because the odor is so subtle. However, when combined with other gases, these emissions can be toxic. The main gases released by cockroaches are hydrogen and methane.
Cockroaches have a complex system of tubes that deliver oxygen and carbon dioxide to and from their bodies. These tubes are attached to the body segments called spiracles. Each spiracle has a valve that opens when CO2 levels in the insect rise and fresh oxygen diffuses into the trachea.
Cockroaches detect the air wave in front of a predator and scurry away. They do so by jumping or climbing. They can also judge their speed by comparing their own body lengths with that of the predator. This way, they can find the fastest way to get away from their predators.
Cockroaches may release gas to increase their overall size. This mechanism is called tidal lung function. It is a type of respiration involving contraction of muscles in the body wall. This function compensates for the constant cross-sectional area.