Yes, rats can swim up sewer pipes and into toilets

Long feared and almost universally reviled, rats have been linked with a multitude of awe-inspiring feats, including wiping out millions of humans through three global pandemics. (Although a recent study exonerated rats for spreading the bubonic plague that devastated Europe in the 14th century. Gerbils are now taking the fall for that one.)

Now there is video footage demonstrating how rats swim up sewer pipes and into toilets.

See The Sydney Morning Herald and National Geographic