This book was a children’s book about a bunch of tiny people. They lived on or around a river, and led a very scary life. Someone – maybe a full size person, or a rival group of miniature people, was quite willing to kill them. And hung dead animals up on trees to scare them away from wherever it was that they wanted to go.
I don’t know how it ended – as a child I only got through the first two thirds one night when my family was visiting another family, and there were no other kids present so I picked up something to read instead. This would have been 1971/1972 in Africa, Lesotho or Swaziland. So the book would most likely have been British in origin. It was kind of dreadful and frightening for a kids’ book, but I have always been curious about how it ended!