The ant genus Melissotarsus is widespread in the Afrotropical region, but less often collected. They possess a number of unusual characteristics. They nest in cavities that they chew out of healthy wood, and many aspects of worker morphology represent adaptations to wood chiselling. Most noticeable are the middle pair of legs that are permanently bent upwards to provide additional leverage against the tunnel roof during chewing, in fact, because of this workers are unable to walk normally in an unconfined space (Khalife et al. 2018). The ants live in a symbiotic relationship with armoured scale insects (Hemiptera: Diaspididae) that they tend inside their nests (Ben‐Dov & Fisher 2010). The nests provide protection for the scale insects, while the ants feed off the wax and other secretions that normally build the armoured coverings of the scale insects (Peeters et al. 2017). Because the diaspidids themselves feed on sap, the ant nests are largely restricted to the living sap‐carrying layers just under the bark, meaning that the ants can potentially kill their host plants by interrupting sap flow. The worker ants do not forage and never leave the nests, of which there is often very little surface trace. Nest breaches are fixed by workers with a mixture of silk and wood fragments: Melissotarsus are some
of the very few ants that are able to produce silk, from glands below the head, and they spin it with specialised front tarsi (Fisher & Robertson 1999).