California Academy of Sciences entomologists, Dr Rick Overson and Dr Brian Fisher, have described six new species of bizarre underground ants in the genus Prionopelta, bringing the total diversity of the genus to 21 species.

Prionopelta seychelles paratype worker, head in full-face view. Image credit: Overson R & Fisher BL.
Prionopelta ants live throughout the tropics of the world. Of its 21 species, twelve (including six newly-discovered species) are known from the Indo-Pacific region, five from the Americas and four from Africa.
One of the six new species, named P. seychelles, is endemic to the islands of Seychelles, while the five remaining species – P. laurae, P. subtilis, P. talos, P. vampira, and P. xerosilva – are restricted to Madagascar.
These ants are tiny. The smallest of the newly-described species, P. laurae, makes a fruit fly look huge.
At 1.5 mm in length and 0.2 mm wide it is a barely visible fleck, skinnier even than the diameter of some single-celled protozoa.
Prionopelta ants are fierce predators that hunt down their prey with dagger-like teeth.

Prionopelta seychelles paratype worker: body in profile and dorsal view. Image credit: Overson R & Fisher BL.
Unlike many ants that are seen marching around at picnics, these ants are either underground or live deep within leaf litter on the rainforest floor – some never catch a glimpse of sunlight their entire lives.
In keeping with their dark and mysterious habits, Prionopelta are part of a larger group of ants that have been dubbed ‘Dracula’ ants, as they are known to engage in the strange behavior of wounding the young of the colony and drinking their blood – more correctly called hemolymph in insects – as a bizarre means of distributing nutrients throughout the colony.
Dr Overson and Dr Fisher have documented their discovery in a paper published in the journal ZooKeys.
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Overson R & Fisher BL. 2015. Taxonomic revision of the genus Prionopelta (Hymenoptera, Formicidae) in the Malagasy region. ZooKeys 507: 115-150; doi: 10.3897/zookeys.507.9303