Myrmecia nigrocincta, commonly known as the jumper ant or jumping jack, is an ant of the genus Myrmecia. The species was first described by Frederick Smith in 1858. Colonies of this ant are abundant in eastern Australia. Ants of this species are known for their ability to jump up to 10 centimetres, and they also have a powerful, venomous sting. Rather than foraging on the ground, M. nigrocincta prefer to forage in trees where they are known to pollinate certain flowers.

Myrmecia is a genus of ants first established by Danish zoologist Johan Christian Fabricius in 1804. The genus is a member of the subfamily Myrmeciinae of the family Formicidae. Myrmecia is a large genus of ants, comprising at least 93 species that are found throughout Australia and its coastal islands, while a single species is only known from New Caledonia. One species has been introduced out of its natural distribution and was found in New Zealand in 1940, but the ant was last seen in 1981. These ants are commonly known as bull ants, bulldog ants or jack jumper ants, and are also associated with many other common names. They are characterized by their extreme aggressiveness, ferocity, and painful stings. Some species are known for the jumping behavior they exhibit when agitated.