Suddenly, Franks realized she had another meeting to get to, and here she was in a room full of free-ranging rats. She couldn’t just open the door and leave—rats would surely escape. But catching each rat and putting it back into the hutch would take forever.

“I think, you know, we should probably get them back in the cage,” Franks said.

“Oh, okay,” said the researcher.

She opened the cage door. The rats streamed back up the table legs and into confinement, where they continued to romp and play. Franks made it to her meeting.

It was an example of how building relationships and channels of communication with rats might allow us to come to understandings with them. “Rats can be quite responsive to human interests that potentially are not even in alignment with what the rats want,” said Franks. (It turns out that this has been shown in laboratory experiments as well, where rats have been trained to participate in procedures they cannot possibly enjoy, such as tube-feeding.)

I admit, and so does Franks, that we are entering unexplored territory here. What does it look like to form social relationships with wild rats? Do we hire rat-catchers who tickle rather than kill? Draw hard territorial lines where they’re most important—in homes, offices, restaurants—while accepting rats on a downtown street or in a park in the same way that we do a pigeon or any other commensal animal?

An idea that seems absurd is sometimes a truth that we haven’t yet accepted. Years after de Chasseneuz represented rats in the court of Autun, one of the strangest animal prosecutions on record gave hints of how the famous lawyer might have fully defended the rats had their trial proceeded.

The case in question was launched against beetles of the species Rhynchites auratus—handsome golden-green weevils—in Saint-Julien, France, in 1587. As with the rats of Autun, the accused were charged with ravaging crops, this time the local vineyards. Again, counsel was appointed to defend the verminous pests.

The prosecution relied on Biblical passages that give humankind dominion over “every creeping thing that creepeth upon the earth”: Since weevils surely creepeth, we were free to decide their fates. The defense, meanwhile, made the case that weevils were a part of divine creation, and God had made the earth fruitful “not solely for the sustenance of rational human beings.”

The trial lasted more than eight months, and at one point the restless citizens of Saint-Julien offered to mark out an insect reserve where the weevils could feed without harming the vineyards. The weevils’ advocates were not placated. They declared the land inadequate, turned down the offer and, as lawyers will, sought dismissal of the case cum expensis—that is, with the accusers paying the weevils’ legal costs. No one today knows how the matter was finally decided, because the last page of the court record is damaged. It appears to have been nibbled by rats or some kind of beetle.

Preposterous? Absolutely. Yet by putting weevils on trial, both defense and prosecution came to agree on one point that eludes us today: Creatures have a right to exist in accordance with their nature, even if it is their nature to make trouble for humankind.