Adventures Among Ants - Mark W. Moffett [26]
From this, it has been determined that an extremely polymorphic species like the marauder ant is likely to have predictable labor needs, because the number of members in each physical caste, or size group, changes slowly, if it can be changed at all, based on the colony’s requirements.4 In fact, the size frequency distribution reveals something about how many ants of each caste a society requires, somewhat equivalent to the distribution of people in different job descriptions in a city.5
To pursue again the earlier metaphor, a colony can be seen as a “superorganism” that functions like the body of an organism, with the number of castes and the frequency of each being analogous to the number of types of cells and tissues and the size of organs. Ant species with small colonies are like the cells in simple organisms in that they have few labor specialists, but marauder ants are intricately specialized. Add the arrangement of the workers in space and their interactions with each other to the numbers and frequencies of the various workers, and one has the “scaffolding” of the superorganism, much as a body is built upon the number, location, and interactions of cells. The parallels are all the more remarkable since both the ant workers in a colony and the cells in a body communicate largely by chemical cues (hormones being a prime example for cells), the biggest difference being that workers are mobile and accumulate dynamically when and where they are needed, while most cells are fixed in place within the body.
Essentially all the participants in the raid front are the little minors. With my photographs, I was able to disentangle the blur of action as these ants brought down a nightcrawler or grasshopper thousands of times their weight. A single minor worker has no more chance of catching such a behemoth on her own than would an equally small worker of a solitary-foraging ant species. But she shares the front with other minors that contact prey at about the same time, and they pile on like tacklers in a game of American football. With this strategy, the chances of capture improve markedly: as in Swift’s tale of Gulliver toppled by the Lilliputians, strength in numbers can’t trump size.
It makes sense for a colony to produce a lot of minor workers and concentrate them at the front. If the prey were confronted by a single media ant instead, even one weighing as much as all those smaller tacklers combined, the larger worker would be less effective at subduing the worm or grasshopper. Though individually weak, minors working together simultaneously grab their quarry at different places and angles, making it hard for a victim to move. The prey is also more likely to slip by a single big worker than by a barricade of spread-out small ones.
Countless times I’ve watched a nightcrawler inching over the ground or a grasshopper resting on its green blade, minding its own business, as a swarm moves toward it with a whisper like a snake in the grass. If it doesn’t respond by reflex, death is certain. At the touch of the first worker, the worm flips back and forth; the grasshopper makes its leap. But out of view in the vegetation, more ants are swarming in. About half the directions the flipping worm or leaping grasshopper could choose will land it deeper among the ants, while the other half will allow it to evade the ants by getting ahead of the raid. Blundering deeper is like colliding with a dragnet with a mesh of the width and strength approximated by the closeness and size of the ants; the