Insects’ extreme farming methods offer us lessons to learn and oddities to avoid
To picture this farm, imagine some dark blobs dangling high up in a tree. Each blob can reach “about soccer ball size,” says evolutionary biologist Guillaume Chomicki of Durham University in England. From this bulbous base, a Squamellaria plant eventually sprouts leafy shoots and hangs, slumping sideways or upside down, from its host tree’s branches. In Fiji, one of the local names for the plant translates as “testicle of the trees.” Some Squamellaria species grow in clusters and teem with fiercely protective ants. As a young seedling blob plumps up, jelly bean–shaped bubbles form inside, reachable only through ant-sized doorways. As soon as a young plant cracks open its first door to daylight, “ant workers start to enter and defecate inside the seedling to fertilize it,” Chomicki says. The idea that ants tend these plants as farmers gave Chomicki one of those surprise-left-turn moments in science. In a string of papers published since 2016, he and colleagues share evidence for the idea...