NOTE: I had several pairs of gerbils in high school.
I realize this is the Daily Mail reporting this article, but I found a number of other articles that support this theory – links below. For those not familiar with the Daily Mail, you can use your favorite or least favorite search engine to find out its reputation. Plague’s origins ratted out: GERBILS not rats were the main cause of the Black Death: https://www.dailymail.co.uk/news/article-2966392/Origins-plague-ratted-actually-GERBILS-main-cause-Black-Death.html, 24 February 2015.
I did some additional research and there is support for this theory –
https://en.wikipedia.org/wiki/Theories_of_the_Black_Death (look for gerbil).
https://www.pnas.org/content/112/10/3020 (link from several of the below articles)
Other Weirdness Wednesdays posts: https://upsdownsfamilyhistory.wordpress.com/tag/Weirdness-Wednesdays/