The silky ant, Formica fusca, can be trained to ‘sniff’ out the scent of human cancer cells. This is the finding of several studies published in 2022 and 2023 respectively in the journals iScience and Proceedings of the Royal Society B by French researchers. After a few minutes of training, the ants could learn to identify urine from mice with cancerous tumors, with a 95% success rate. A number of clinical tests still need to be developed before deployment at scale can happen.