Ants at war
In the American desert, where resources are scarce, honeypot ants wage war without end. Rob Dunn asks if we can draw parallels between ant and human conflict.
DID YOU KNOW?
- Ants have independently evolved honey storage in deserts around the world: Myrmecocystus in North America,Camponotus and Melophorus in Australia, other kinds in other places. Repletes hang. Honey is stored. Tough times are overcome through pluck and reserve.
- But ant societies are not the only ones for which history repeats itself. In what is now the south-west USA, Native Americans have long plundered the repletes of honeypot ants, lying prone on the hot earth to dig them out with sticks. Amazingly, the same also happens in Australia, where a totally unrelated honeypot ant is harvested by a culturally unrelated race of people.
- If there is a lesson here, it is this: in a desert, ants will work out how to store sugar, and, if they store sugar, desert people will work out how to find it.
- Grasshoppers store food by getting fat. That is enough for them and so they have diversified and persisted. It’s the same for bears and crickets. They have no other way, no place to put anything else they might gather, nor any way to keep it from rotting. In this they are like our ancestors or, for that matter, the ancestors of ants.
- But then the ability to store food evolved, many times. Moles store half-eaten (but still living) earthworms. Squirrels store fungi. Carnivores store meat, bowerbirds fruit. Shrews store snails. Wasps store paralysed spiders and nearly everything stores seeds.
- And then there are the ants, some of which cache seeds, while others hang up honey. Ants are the only group in which a special caste of individuals has evolved to store food. We can be thankful for that. I have plenty of relatives, but there are none from whom, even in times of great need, I’d be pleased to receive a dose of regurgitated honey.