Cats and rats have been helping Colombian police sniff out land mines. The rats are trained to sniff out landmines and are taught to freeze when they detect one. The problem is that the rats have not been doing the job effectively because they are frightened of predators. Putting the rat into a cage with a cat helps the rat becomes used to the presence of possible predators so they can concentrate on their job. The cat’s claws are covered so they cannot injure the rat.