The jack jumper ant (Myrmecia pilosula), is a species of venomous ant native to Australia. This species is known for the ability to jump long distances. These ants are large, approximately 12 to 14 millimeters.

Jack jumper ants are primarily active during the day, with a life expectancy of over one year. Workers are gamergates, allowing them to reproduce with drones, whether or not a queen is present in the colony. 

The ant venom causes about 90% of Australian ant allergies. In endemic areas, up to 3% of the human population has developed an allergy to the venom and about half of these allergic people can suffer from anaphylactic reactions, which can lead to death on rare occasions.

The jack jumper ant genome is contained on a single pair of chromosomes (males have just one chromosome). This is the lowest number known (indeed possible) for any animal.