Richardson said he hopes this study nudges city officials and scientists to gather more data about rats. Banner image of a roof rat (Rattus rattus) by Rhett A. Butler/Mongabay.

Count em! One, two, three - anyway... there are SEVEN wonders of the ancient world, so let's sing along to them in this new Horrible Histories song!

We also say hello to Rattus Rattus's brand-new girlfriend Ratalie, who Rattus Rattus is hoping will be impressed by a romantic dinner of 'cockroach in jus de rubbish bag' ...