part_of Anatomical part abdominal segment number 2 abdominal segment number 3 abdominal segment number 4 spiracle SIBO:0000502 ilma 2007-12-20T04:04:00Z sibo Spiracle- An orifice of the tracheal system by which gases enter and leave the body. Ants have 9 or 10 spiracles on each side of the body. The prothoracic spiracles have been lost, so the first opening occurs on the mesothroax. (Bolton, B. (1994). Identificstion guide to the ant genera of the world. Cambridge, Mass., Harvard University PRess. pp.1-222).