I've been too busy to go down to the brook much this week, but here's a latrine, I think.
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At the back of Edward German Drive there are currently lots of burrows, but I don't know whether they belong to water voles or brown rats. Rats' burrows often have an untidy heap of soil outside, and water voles' are supposed to have a grazed area nearby called a 'lawn', though personally I've never seen one. But these burrows are just holes, so I can't tell.