Two days after the encounter between the ants and the dinosaur, on an equally sweltering afternoon, the inhabitants of the ant town were shaken by another quake. They scampered up to the surface and were met by the towering figure of a Tyrannosaurus, which they straightaway recognised as the same one from before. It had hunkered down and was scouring the ground for something. When it saw the colony, it lifted a claw and jabbed at its teeth. The ants understood immediately, and in a single uniform gesture all 1,000 of them waved their antennae excitedly. The Tyrannosaurus placed one of its forearms flat on the ground and allowed the ants to climb on. And just like that, the scene from two days earlier was replayed: the colony made a meal of the scraps of meat stuck between the dinosaur’s teeth, and the dinosaur was relieved of a minor dental discomfort.

For some time after that, the Tyrannosaurus routinely sought out the town of ants so they could pick its teeth. The ants could feel its footfalls from a kilometre away and were able to accurately distinguish them from those of other dinosaurs. They could even tell from the vibrations in what direction the Tyrannosaurus was moving. If it was heading towards the town, the ants rushed eagerly to the surface, knowing that their food supply for the day was assured. Even though one party in this cooperative endeavour was very large and the members of the other party were undeniably very little, it didn’t take long for the interactions between the two to become well honed.

One day the vibrations coming through the ants’ earthen ceiling sounded different, unfamiliar. When they streamed up into the clearing to investigate, they saw that their partner had brought along three other Tyrannosaurus rex and a Tarbosaurus bataar! All five dinosaurs gestured at their teeth, requesting the ants’ help. The mayor, recognising that its colony couldn’t possibly undertake such a massive task on its own, sent several drones post-haste to contact other ant towns in the area. Soon, three mighty rivers of ants came pouring in from between the trees, and an army of more than 6,000 ants converged on the clearing. Each dinosaur required the services of 1,000 ants, or, rather, the meat between the teeth of one dinosaur could satisfy 1,000 ants.

The next day, eight dinosaurs came to have their teeth cleaned, and a few days later that number increased to ten. Most of them were exceedingly big carnivores and they had a correspondingly big impact on their surroundings. They trampled the nearby cycads, enlarging the clearing significantly, and at the same time they solved the food problems of a dozen ant towns in the vicinity.