I had heard of APOPO rats a few years ago because there was a rat which had been awarded a bravery award. What luck that I ended up in the same town as the rats.
Sadly they are nocturnal so if you want to see them you have to get up at the crack of dawn to watch them being trained. They have about 50 rats in training and we saw some at various stages of accomplishment.
The less experienced rats would stop and preen themselves in the middle of the task while others are more focussed on the task. I was surprised to see them wearing a harness and tied to a piece of string wound around the boots of two workers.
Once the rat has done a width of the ground, the workers move up half a metre and then rat goes back along the line. When they smell TNT they stop and scratch the surface of the earth. They are then rewarded by a bit of banana.
It seems to work well and these rats are sent all over the world but mostly to Angola and Cambodia where they save the lives of many villagers who lose limbs to old landmines.
The workers at APOPO look after the rats and get attached to them, even putting suncreen on their tail and ears because, being nocturnal, they get sun burnt. They need to be socialised and used to working during the day and working with humans.
It’s a long training process but they do vital work and seem to enjoy it.