If you like, they are a body without a skin. Each individual ant acts with a purpose and has a specific role to play. Like cells they differentiate in their purpose of being. Some ants will act as guards defending the nest and protecting other ants (in a similar fashion to white blood cells). Other ants are worker ants, basically undertaking a whole variety of tasks from cleaning, to building, to carrying, to tending nurseries and eggs; some are scout ants searching for food; but the majority of ants you see are females. This is because all worker ants are female, as are the soldier ants, the scout ants, and obviously the Queen. As they come from the same queen they are also all sisters. The males do exist but are purely there to ensure the next generation – after fulfilling that role they generally die or leave the nest (and then generally die).

Ants are immensely strong – they can carry between 10 and 50 times their own body weight, which is equivalent to me lifting my Mitsubishi Colt with one arm! This is because they don’t have a large body mass and therefore proportionally more muscle can be used to lift heavy loads.

To date 10,213 ant species have been identified, however, it is estimated that there are over 20,000 species worldwide. So which ones do we know about in Africa that we commonly see? Well let’s talk about two very visible and well known species. The first has got to be the African army ant – siafu (Dorylus species), otherwise known as the ‘safari’ or‘driver’ ant. They are called army ants because they exhibit ‘legionary’ behaviour – just imagine the French Foreign Legion – these are hard ants! This species of African ant above all others has the
ability to strike fear and dread into all who come across it….usually because by the time you realise they are there, it is biting you, which means about another 50 are also somewhere about your body and moving in for the kill!

This species lives on aggression. It is literally pre-programmed to attack anything that moves…..and I mean anything. If you throw a lighted cigarette into one of their moving columns they will attack the lighted end (obviously killing them in the process) as they are also attracted by heat sources. These are small to medium reddish brown ants that we see moving rapidly in thick columns (they can travel up to 20 metres an hour). If you dare inspect these columns you will see they are protected by a wall of soldier ants that are interlocking and facing outwards with open jaws ready to snap at anything within reach. If you come across the columns of these ants you might still see the same column moving the next day…and the next day…and the next day.

That is because this species of ant can have colonies of up to 20 million individuals Recall what I was saying earlier about each ant representinga cell within a larger organism……So why are they moving and what are they doing? Well, they are moving because they are a seminomadic species. They are a mobile ant whose colonies constantly shift from place to another.

They do not have a fixed abode. This is because they clear an area of all possible food and so are forced to move on. Half the time they spend moving from one place to another and the other half they spend foraging and collecting food. They basically eat anything they can get their jaws on but, realistically, this generally means insects and small vertebrates. The danger from these ants is when they stop moving in columns. At this stage the colony has finished moving and now they exhibit foraging behaviour….or in other words
they swarm.

Whilst working in the bush in many African countries, I have had the misfortune of walking into the middle of a swarm of army ants. As you can imagine, this is a painful experience, made even more painful by the fact that (especially in a forest) you do not know which direction the swarm is coming from or going to. A fast exit in a line of one’s choosing is the best strategy. They also attack at night. On several occasions I have been in my
dome tent in the bush when it has been attacked by army ants. One usually awakens to the sound of a scratching noise coming from around the tent. When you have eliminated the possibility that the noise is originating from your friend sleeping in a nearby tent (!?!), and have then switched on your torch, you notice a couple of thousand small jaws all trying to bite their way through the tent liner towards your body. On the first occasion this happened, I was determined to fight them off. This entailed me sitting inside my tent with a head torch and a roll of sticking plaster.

Whenever an ant made it through, I patched up the hole with stickingplaster (and killed the ant). However, this seemed to make them more aggresive and agitated.

The battle lasted for several hours until they eventually moved on. It was nearly dawn, I was exhausted, and my tent was shredded - the next time this happened I opened the tent and ran…thus saving time, effort, and the cost of a new tent. By the way, the male of this species was unknown for a long time but also constantly seen. This was because it was virtually impossible to get into the middle of the colony of this species to investigate (for obvious reasons), however not so long ago the male army ant was identified – it is the rather
annoying ‘sausage fly’ that comes buzzing around lights at night.

The next species of ant I want to talk about has a similar behaviour to the African army ant but more akin to the SAS than the French Foreign Legion in military terms. These are the large black ants, up to an inch long, that we sometimes see on their own or in small columns of a couple of hundred. This group is commonly known as the Matabele ant or stink ant (Pachycondyla species) named after the Matabele warriors. This was one of the first species I studied in detail in Africa, which involved sitting outside one of their nests in a hammock for 6 weeks from dawn to dusk and recording their behaviour from the time of immigration into a nesting site to emigration. Such is the life of a zoologist! Let’s start from the beginning. These ants should be considered as wingless wasps (they sting – 10 stings can apparently paralyse your arm – be careful). Wasps, bees, and ants are all in the same order – Hymenoptera. The Matabele ant eats termites (it’s a termitophage).

They live in colonies of about a couple of thousand ants. Like the African army ant, they forage a certain area and then move on to a new site, often returning to the old area at a later date when the food supplies (termites) have regenerated. Some of these ants fall into the caste known as ‘scout’ ants. It is the job of these scout ants to locate the potential supply of termites. As the name suggests; they operate on their own and are often seen
moving swiftly across the ground searching for termite colonies to raid at a later date. When they find a suitable termite colony they return to the ant nest laying down a pheromone (scent) trail in order to determine the correct direction back to the termite colony. When the scout ant arrives back at its nest, it releases another pheromone which gathers together a raiding party of a couple of hundred worker ants. Once gathered, they set off towards the termite nest, led by the exact same scout ant that found the termite colony in the first instance, following the original trail laid down by that individual scout ant. If you see these columns and remove the lead (scout) ant in the column, they will stop in confusion. That is because only this one ant knows the path to the termites. If this scout is removed, the raiding party will regroup and eventually return back to the ant nest following their own scent trail. Anyway, at about one metre away from the termite colony the raiding column will stop. The lead scout ant then releases an attack pheromone and the ants became extremely aggressive. Then all hell breaks loose and the ants attack the termites with full-on rage. They rip open the termite foraging tunnels and dive in biting and stinging as they go. Full-on battles occur between the termite soldiers and the ants. After about 20 minutes the raid is over. Some ants have been killed but that is nothing compared with the number of termites. The dead termites are gathered; the trail-following pheromone is released, and the ants return to their nest where the termites are fed to the next generation of ants. Next time you see these ants take some time out and follow them – you won’t be disappointed!

So that about covers my short insight into ants and the general behaviour of two species you may commonly encounter upon your travels in Africa. If you want to know more there is a very good book– the text beyond all other books on ants: - “The Ants” by Edward O Wilson and Bert Hölldobler (1990) - Harvard University Press, ISBN 0-674- 04075-9.

Dr. Julian Bayliss
Mulanje Mountain Conservation Trust
jlbayliss@yahoo.co.uk