These are probably the most dangerous animals in Tasmania. They are a small member of the "Bull ant" group (Myrmecia spp.).
Bull ants get their name from never telling the truth- in fact they don't say much at all. Which is a pity, because if they were to swear
loudly before swarming up your trouser leg one might have some warning of their intention. Jackjumpers deliver an incredibly
painful sting, and people who are allergic to bees and wasps can and occasionally do die as a result of a sting from these ants.
They are one of the few species of jumping ants. They only seem to jump in warm weather, when they don't need a jumper.