FOR insects, heavy breathing can be fatal. If resting butterflies breathed all the time, so much oxygen would build up in their delicate bodies that it would kill them.
Most animals use proteins such as haemoglobin to control the amount of oxygen that gets to their tissues. But insects get their oxygen directly via a network of tubes linked to openings in their sides called spiracles. Several species, including ants and butterflies, rhythmically open and shut their spiracles when they are inactive, which entomologists assumed was a way to conserve water or survive in environments high in carbon dioxide.
But…
