Diederik van’t Hof, owner of Roof Rats, checking a trap with Godwin Jere.
Diederik van’t Hof, owner of Roof Rats, checking a trap with Godwin Jere.
For two weeks there was a showdown in the Msawawa informal settlement, just outside Kya Sands, to the west of Johannesburg.

It was high noon though played out at night and the rule was simple: Who kills the most rats wins.

This unlikely contest pitted the City of Johannesburg against a team of oddball inventors, who had developed a trap they believed could finally end Gauteng's rat problem.

Egbert Harmes, Diederik van't Hof, Abel Mukwevho, Godwin Jere, Denis Munthalie and Simphiwe Makapela, the team behind the new rat trap.


Across the test area, 20 examples of what the inventors had named the Hamelin trap were placed alongside wire cages, the preferred method Council uses to catch rodents.

After 14 days in September, the inventors claimed victory.

“We beat them hands down,” recalls Diederik van’t Hof: “Their traps got stolen and disappeared.”

The figure was 25 rats for the City of Johannesburg and 81 for the inventors.

Jan van Niekerk, an operations manager in the City’s vector control unit, who was running the trial, reluctantly admitted that the Hamelins did kill a lot of rats.

For the team, this was both their Eureka and their Viva moment. It had taken them 37 attempts to come up with a rat trap that was both cheap and deadly.

The Hamelin is the creation of a team comprising two professional speakers, a kilt-maker-cum-engineer, and an ex-tour guide.

It was the two professional speakers, Abel Mukwevho and Simphiwe Makapela, who got it all rolling.

“We were sitting in Soweto and the place we were at had a lot of rats. So we started thinking of a plan of how can we get rid of these rats,” says Mukwevho.

The two came up with a design and patented it. Then they looked around for someone who could work with them on the project.

This eventually led them to Van’t Hof, who now runs a company that cleans ceilings and roofs.

With engineer Egbert Harmse, the Afrikaner kilt-maker, they began working on improving Mukwevho's and Makapela’s design.

It wasn't easy. They soon realised they had to lose the tubing in the original design. Rats don't like wandering into strange tunnels, they quickly discovered.

Harmse even made a batch of rat pheromone. “Now that really stinks,” he recalls.

Rat pheromone turned out to be impractical, because it evaporates too fast.

Eventually, by number design 37, they felt they had the right thing.

Number 37 works in a manner similar to the swing-top dustbin lid. The top of the trap is flush with the ground and when the rat walks over it, its weight causes the door to open and the rodent to fall into a bucket below. The bucket is placed in a hole dug in the ground and is filled with water. The rat then drowns.

There is also a special knack as to which bait is used. Rats are known to exhibit a trait called "bait shyness". “You have to use bait that is generally found in the area, like chicken bones, or bread,” explains Harmse. “Try something like peanut butter and they won't eat it.”

The Hamelin may no longer be slugging it out against the City’s cage traps, but they are still on trial and continue to chalk up an impressive kill rate.

In four months the Hamelin traps have caught 1197 rats in Msawawa. “That works out to an average of 1,56 rats per trap, a night,” explains Van’t Hof.

Some of those rats collected have surprised even the old hands in the varmint-hunting business. “We were told that we wouldn't find rats weighing more than 500 grams. Well, we have found bigger ones than that,” says Van’t Hof.

The biggest they caught was a beast they nicknamed Ratzilla. This rat clocked in at 661g.

The biggest rat caught during a pilot project by Roof Rats at Msawawa informal settlement, Kya Sands.Picture: Supplied


“So far we have caught two rats that were over 600 grams,” Van’t Hof says.

What the team have noticed lately is that the respective weights of rats they are catching are on average declining. It could mean that they are making a dent in the number of rats in the test area.

It is statistics like these that make the team believe that their device could be rolled out across Joburg, and if enough are rolled out , could put an end to the city’s rat problem.

However, Van Niekerk has a few problems with the design. His concern is that the animal rights organisations won't like the way the Hamelin drowns its prey. Also he worries that water in a bucket could present a drowning risk for toddlers.

But the locals of Msawawa say they have noticed a decline in the number of rats in the area.

“They just keep begging us for more traps,” says Makapela.