Tag Archives: Mutant rats

Commercial Pest Control – Myths Part II – The Giant Mutant Rat

Giant Mutant Super Rats! – A sensationalist headline?

In Part I of this series we discussed the headline- ‘Super Rats are Immune to Poisons’ ; in Part II we will look at media headlines claiming that ‘Plagues of Giant Rats are taking over the UK!’.

What are the myths and hype surrounding claims of giant rats in many areas of the UK? We will start with the photographic evidence commonly used in the media:

1. The Giant Rat being held up to the camera

Photos in the media regularly show  a person holding a dead rat up to show its large size. These photos invariably show a rat being held up using ‘waste nippers’ or some similar extending device. This then creates an illusion of increased size using ‘perspective’, a common camera trick. The photo below attempts to show how perspective can be used to create this illusion.

How perspective can alter the size of a 'Giant Rat'.

How perspective can alter the size of a ‘Giant Rat’.

If a giant rat had been caught then some form of scale would help to confirm the finding. Placing the rat on the ground and photographing it next to a ruler or tape measure would be an obvious and easy method; or even keep it for a few days in case anyone wanted proof (preferably stored somewhere cold!).

In all the cases I could find in the media, the rat had not been kept as evidence and the photos were misleading.

2. A different species?

Whilst the Brown Rat (Rattus norvegicus) dominates in the UK, other larger species of rat have been filmed with some misleading results. A quick search on YouTube and you can find a clip of a large rat sitting on a toilet with the headline ‘Giant Rat Emerges from the Toilet’. This video has been shown on many websites, with various headlines and here it is claiming to show a ‘Brown Rat’ (Rattus norvegicus). The rat shown in the video is actually a pouched rat (Cricetomys gambianus) which can grow significantly larger than R. norvegicus and they are commonly kept as pets.

Whilst the pouched rat has become an invasive species in Florida, U.S., there are no confirmed colonies living wild in the UK.

More Information:

The Brown Rat (R. norvegicus) varies in size (body and tail) from approximately 12 inches (30cm) to as much as 18 inches (48cm). More information can be found following by this link to the BPCA website.