Sheep tick (Ixodes ricinus) spiracle. coloured scanning electron micrograph (SEM). This spiracle, or air pore (centre), is part of the tick's respiratory system. Air diffuses into the spiracle and circulates the body in a network of tubes called tracheae. Waste gases exit the body through the spiracles. The hairs around it prevent foreign bodies entering the system. Magnification: x130 when printed at 10 centimetres across.