If you happen across a worker ant of Pachycondyla tarsata (previously known as Paltothyreus tarsatus), you will have no need to look them up in a book to identify them. You will probably be able to tell what kind of ant they are by their foul odor. The smell they produce is so bad that they are called African stink ants.
Found in central and southern Africa, these large dark gray/black ants are up to 3/4 inch (19 mm) in length.
(Photograph by April Nobile / © AntWeb.org / CC-BY-SA-3.0, retrieved from Wikimedia)
All ants talk to each other and defend themselves using odors. We humans can smell only some of the scents that ants use to communicate, which range from pleasant -like coconut oil- to horrible enough to earn the title "stink."
African stink ants produce their foul smell in their mandibular glands. They release the odor only when they are alarmed. Some of their trail and alarm pheromones have been identified.
Pachycondyla tarsata are known to prey on termites and also scavenge other arthropods. Bert Hölldobler showed that these large ants see well enough to memorize the images of the forest canopy above them when they move about foraging and thus can remember the way back to the nest.
In the following video, you can see the African stink ants raiding a termite nest. The video also contains scenes of lions attacking a water buffalo. If you would like to avoid that, let the video load and then view the segment between 7:00 minutes and 9:00 minutes (the bar pops up in the bottom of the screen if you run your mouse over it).
(Sorry, the video is not in 4D, like a recent kids movie.)
These ants are definitely on my life wish list (behind Harpegnathos saltator). My husband went to Africa a few years ago, but all he brought back were pictures of these (grin).
For more information, try AntBase's Ants of Africa
Hölldobler, B. 1980. Canopy orientation: a new kind of orientation in ants. Science. 210: 86-88.