Mystrium camillae - "The Dracula Ant"
This is a rare species that is very difficult to find in the wild and is not often offered for sale. It is in demand by specialized collectors due to its unusual habits and structure.
The workers are 3-4 mm in size and brown / brick red, covered with short hairs. Workers are variable in size with the smaller workers caring for the brood and the larger ones acting as hunters. Queens are distinguishable as they are around 5-6mm and have a distinct larger thorax and abdomen.
Its natural habitat is well-developed mature forests where they create nests under fallen branches or old tree stumps. Colony size tends to be small, usually less than 200-300 workers, and can have several queens.
In the wild, their food is reported to be small centipedes. Their long mandibles are adapted to gripping the fast-moving centipedes, and then hold them in place allowing the ants to sting in the soft area between the body segments. Foragers carrying out this task need to have strong mandibular muscles combined with long mandibles. This adaption compromises their efficiency in regard to brood care. Hence there are large workers that are specialized in foraging and smaller workers that specialize in brood care.
The mandibles of this species are the fastest known moving animal appendages, snapping shut at speeds of up to 90 meters per second (speeds of up to 200 mph), making it the fastest animal movement on record. Among ants that power-amplify their jaws, the Dracula ants are unique because instead of using three different parts for the spring, latch, and lever arm, all three are combined in the mandible. Unlike 'trap-jaw ants', whose powerful jaws snap closed from an open position, Dracula ants power up their mandibles by pressing the tips together, spring-loading them with internal stresses that release when one mandible slides across the other, like a human finger snap.
Their prey is often arthropods, especially centipedes. Once prey is caught it is taken back to the nest and simply placed near the larvae which will then consume it without any help from the workers.
The workers of this species do not take food directly themselves, but drink or suck the blood/juice (hemolymph) of their larvae, hence the name "Dracula ants" or "Vampire ants". In reality, they perform a form of non-destructive cannibalism, by cutting a hole in the skin of their larvae to feed on the exuding fluid. This practice, also known as Larval Hemolymph Feeding (LHF), consists of ingestion of hemolymph dripping from punctures made by adults in the larval integument. However, this action does not seem to harm the larvae, which continue growing and eventually emerge as normal adults.
They seem to adapt well to captivity, however, feeding is a challenge as their natural food is not available. We have been trying several alternative food sources over the past month. We have found that they will eat termites and small mealworms (size 5-8mm). They will probably also take newly emerged crickets and possibly fruit flies. It was also noted that some workers congregated around the moist ground where a sugar/water mix seeped out of a feed tube - suggesting they will take sweet substances like some other primitive ants such as Diacamma.