Rats have been lumbered with a terrible reputation ever since they spread the Black Death back in the 14th century.
They’ve been consigned to the shadows for hundreds of years, lurking in sewers and scraping by on whatever they can scavenge from the streets.
However, they could be in line for an exciting career change after a group of rats aced an in-depth wine sniffing test.
Researchers at four universities (London, Lincoln, Trento and Vienna) joined forces to see if rats could distinguish between the aromatic profiles of two wine varieties.
They placed nine rats in test chambers and encouraged them to sniff wines: four Sauvignon Blancs, from France and Chile, and four Rieslings, sourced from Germany, France and Austria.
The researchers gave the rats a treat when one wine was present, so they learned to associate a particular aromatic profile with a reward.
After sniffing a wine, the rat had to use its nose to poke a particular lever. If the rat guessed correctly, it would receive food, while an incorrect response would result in a timeout penalty.
Training continued until the rats were getting 80% of their responses correct for three consecutive sessions.
They were then given an exam. The rats returned to the chamber, where they began sniffing wines, some of which they had been trained on, and others that were new.
The results were emphatic: they nose-poked the correct lever 94% of the time on wines they had been trained on, and 65% of the time on new wines made from the same grape varieties.
Researchers wrote that the results ‘indicate that a nonhuman mammal can discriminate between complex odour categories. This finding is consistent with the idea that many nonhuman mammals have olfactory abilities that match or exceed those of humans’.
It suggests that rats could come out of the sewers and move into the restaurant business, serving as a new breed of elite sommeliers.
However, while most of the participants dazzled with their olfactory prowess, a rat called Peanuts let the side down. He completed the training phase, but he struggled when sniffing new wines during the testing, so he’s not in line for a top job just yet.
