Subfamily Formicinae

Named for the ant genus Formica

Formicines retain some primitive features such as the presence of cocoons around pupae, the presence of ocelli in workers, and little tendency toward reduction of palp or antennal segmentation in most species, except subterranean groups. Extreme modification of mandibles is rare, except in the genera Myrmoteras and Polyergus. On the other hand, some members show considerable evolutionary advancement in behaviors such as slave-making and symbiosis with root-feeding homopterans. Finally, all formicines have a very reduced sting and enlarged venom reservoir, with the venom gland, specialized (uniquely among ants) for the production of formic acid. [source: wikipedia.org]

descriptive charactersitics and classification (wikipedia.org)