The rats learned to signal for pangolin scales, rhino horn, elephant tusk and African blackwood, which is popular for use in musical instruments. Eventually, ...

All trained rats wear a harness equipped with a ball on their chest. When they detect a target, they signal their trainer by pulling the ball, which triggers a sound to indicate their discovery.

The rats sniff samples for tuberculosis, and they signal when a previously negative TB result is actually positive; then APOPO re-tests it with a more sensitive process to confirm positivity.