Environment Agency staff have spent the day dealing with an emergency at a canal in Grantham after hundreds of dead fish were discovered this morning.
It's thought they died through lack of oxygen caused by the hot weather.
Chemicals have now been added to the water to bring the oxygen levels back to normal.
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The game was invented in the Birmingham between 1943 and 1945.
He stayed low so he wouldn't trip the alarm.
They are wild animals and should not be kept as pets.