Herding Behaviour in Children

While on the subject of predators and children I thought I might as well tell this little story.

In Volume 1 of Narrow Roads of Gene Land, in the introduction to his paper Geometry for the Selfish Herd, William Hamilton talks about coming across a copy of Francis Galton's Inquiry into Human Faculty in a second-hand bookshop:

... Re-reading it after my interest (or irritation) over aggregation had been re-stimulated by other more holistic interpretations, I noticed some remarks about cattle in South Africa. These led me to an obscure paper by Galton, which I think few can have read. His argument was on the line I was already inclined to. Galton, I was surprised to be reminded in the book, had personally explored Damaraland in southern Africa and had observed for himself half-wild cattle in a terrain where lions and other large predators were still common. To see is to sympathize, especially when the observed animal is a mammal; moreover Galton probably personally experienced the sensation of safety from surprise attack when walking in the savannah among cows as compared to when walking alone. ...

I have had a rather similar experience to the one described above, not in the wilds of Africa but in central Reading. When my daughter was young I often used to take her and her friends out to play in the field next to our flats (since built on, alas). Usually I would take a ball with me and as soon as we got into the field I would kick it as high and as far as I could, and the children would scamper off after it. Then I would get out a book or paper to read while the children played. For some reason this day we didn't have a ball with us. Instead the children were running around me chasing each other in circles of about 3 to 5 metres radius. This 'electron cloud' of children kept up with me as I walked out towards the middle of the field. Then suddenly, without anything being said, the children were all orbiting within 2 metres of me - right under my elbows. I looked up to see what had caused this. A man with an alsatian dog had just come into the far corner of the field, the dog was off its leash and running up and down along the far hedge. The children must have seen the dog out of the corner of their eyes and subconsciously recognised it as a danger; enough of a danger to adjust the size of their 'orbits' but not enough to stop their game. The dog didn't come anywhere near us but the children continued to play within their smaller orbits until the man and alsatian left the field a few minutes later.