Acrobatic Moorhen

Very odd today. While waiting at traffic lights, in a rhyne to my left I spotted a moorhen. Nothing unusual in that except this one was on top of a few reed stems, about 3-4 feet up and whilst struggling to keep its balance, seemed to be pulling the seedheads off the stems. I've never seen this from a moorhen before, and not entirely sure what it was doing, or why. Unfortunately couldn't spare time to investigate more, but an interesting diversion from the car infront of me.