they were by Grafham Water Cambs this morning.
thanks for your help

Thanks for the ID, Mark. I had been wondering whether these were the larvae of one of the processionary moths.Mark Colvin wrote:These are Brown-tail Moth larvae, Euproctis chrysorrhoea. The larvae are well-known for their urticating hairs, which can cause extreme irritation if in contact with human skin. They feed in communal webs on the leaves of plants such as hawthorn, blackthorn and bramble.