In order to detect landmines in the most efficient and effective manner HeroRATS use two complementary techniques that can be used at different stages of the demining process.

Rats are able to detect metal and plastic encased landminesDirect Detection
In the field, leashed rats systematically search the mined areas and pinpoint the location of the buried explosives by scratching on the top soil. Detection of buried landmines, is the last step before landmine removal, and it is one of the most crucial, but also tedious jobs of the demining process.

Once the boundaries of a minefield are delineated, the task of locating and removing the landmines and UXO can start. To speed up the process of demining, mine detection rats are used to directly indicate the positions of buried landmines. On average, it takes a rat a half an hour to search a 100m2 box. And in general, mine detection rats cover 200 sqm per day.

The rat is guided by a search string, which is connected between its two trainers. The rat moves systematically up and down the search string, processing lane by lane through the suspected box. Both trainers take position at opposite sides of the box in the safe lane, fixing the search string to the lower leg. When a rat reaches the end of the box, the operators make a lateral step, and the rat moves into the next lane. A box or lane system provides the safe access lanes for the trainers. APOPO is using 5 by 20 meter boxes, which means that the rat has to search 40 lanes of half a meter to clear one box.

The rat indicates the position of a landmine by scratching the surface at the spot. Being lightweight, they do not set off the explosive devices. In a training situation, the trainer clicks upon a correct indication by the rat and the animal moves to the trainer to get its reward. A second person, the observer, takes notes on the behavior and performance of the rat while working.
Typically, one to two rats are used consecutively to search an area. The number of rats to be used depends on the risk assessment of the area, operational scenario and the combination with other search techniques. Quality control behind other detectors or a confirmation search behind a mechanical clearance will require less animals compared to primary detection.

After the rat has been fully trained on the training fields in Tanzania, a series of blind tests is carried out to assess its performance. If the animal meets the desired requirements, it will be selected for de-mining operations. As with dogs, the rats are re-calibrated on the specific mines found in the demining operations, before being deployed.

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Remote Explosive Scent Tracing (REST)
Instead of taking the rats to the minefield, Remote Explosive Scent Tracing (REST) brings the scent from the mines to the rats. HeroRATS trained to detect the explosives on field samples, can help to reduce the minefields to its actual boundaries.

Demining organizations spend most of their effort searching for mines
where there are actually none. The REST technology is an effective tool
which could help determine which areas are free of explosives, thereby
opening up major parts of the suspected minefields.

REST technology is still in the research phase and has not yet
qualified for accreditation according International Mine Action
Standards. In essence the technology works via a sampling team, walking
in the safe lanes created by demining vehicles, taking samples of every
100 meter road stretch through a pump they wear on their back. The
backpack pumps draw the air and dust from above the road surface
through a filter, which is designed to collect the explosives emanating
from the mines and UXO.

Trained rats then can systematically evaluate these filters in a
laboratory setting, and will indicate the occurrence of explosive
traces on the filters. A positive indication results in a highly
suspected road stretch, which is earmarked by the demining company for
thorough follow up.
Every day, about 30 rats evaluate soil samples spiked with low
concentrations of TNT. Combined with other technologies, the REST
technology can provide fast opening of roads in post war countries for
the delivery of emergency relief.

Learn more about the work done and areas cleared in Mozambique in our Mozambique report