sewer

E. coli is the field's main "workhorse" says Prof Wallace, who has also genetically engineered it in the lab to turn plastic waste into vanilla flavour and fatberg waste from sewers into perfume.

Because rats live in drains, sewers and burrows, and emerge mostly at night, counting them is nearly impossible, so estimates on rat population figures vary.

If a home is seated too low, it won’t be able to properly connect sewer lines and storm drains, which require a high-to-low slope.

The rains have stranded millions mid-commute, left cars floating in streets that have turned into rivers and caused outbreaks of leptospirosis, a liver ailment that spreads through the excrement of sewer rats.

The city that Tom Bradley has led with impassive aplomb for 17 years is frayed at the edges, with aging sewers and inadequate housing stock.