 Myrmecia is one of the best @-@ known genera of ants . Myrmecia ants usually display defensive behavior only around their nests , and are more timid while foraging . However , most species are extremely aggressive towards intruders ; a few , such as M. <unk> , are timid , and the workers retreat into their nest instead of pursuing the intruder . If a nest is disturbed , a large force of workers rapidly swarm out of their nest to attack and kill the intruder . Some species , particularly those of the M. nigrocincta and M. pilosula species groups , are capable of jumping several inches when they are agitated after their nest has been disturbed ; jumper ants propel their jumps by a sudden extension of its middle and hind legs . M. pyriformis is considered the most dangerous ant in the world by the Guinness World Records . M. inquilina is the only species of this genus that is considered vulnerable by the IUCN , although the conservation status needs updating . 
