Snails sniff out pollution levels
Russian scientists are using giant African snails to monitor pollution from a sewage incinerator.
They are attached to sensors that will show them getting sick if they take in too much bad air at the St Petersburg waterworks.
Some environmentalists say it is a publicity stunt but waterworks company Vodokanal says the 8in-long snails can detect compounds produced in concentrations too low for conventional gauges to detect.
The same company is also using crayfish to monitor the quality of city water.