A closer look
It turns out lungs are just a suggestion. Because ants are so small, a complex respiratory system powered by pumping lungs would be completely inefficient. Instead, they rely on a passive network of tiny tubes called tracheae. Oxygen slowly diffuses in through tiny holes along their abdomen called spiracles, and carbon dioxide quietly drifts out. This system perfectly suits their tiny bodies but physically prevents them from ever growing to the size of a dog, saving us all from a horrific sci-fi movie scenario.
