Joan Riley writes

Can anyone tell me what we might have by our stream? We have a stone
dyke wall about 20ft from the back door with a little stream on the
other side which has boggy pools alongside it in this spot. The last
few nights we heard this funny noise which sounded like a motorbike in
the distance, or a cat purring. The frogs we had at our last house
made a sort of intermittent burping/croak noise but this is more or
less a continuous "r r r r r r". I had a look with a torch when I
first heard it but as I can't climb the wall I was some distance away
and couldn't see anything. The pools aren't much more than puddles
but I can't see any spawn in there from this side of the wall.

Could be frogs. Ours were making a fairly continuous noise the other
evening - a rather nice soothing sound.
--
Kay