Whilst on the North Yorkshire Moors for a holiday in August, we saw some Common Cotton Grass so I took a photo. It was only when I was looking at the photo later on my computer that I noticed the small caterpillar tucked away under the flower head.

It looks decidedly tufty, almost like a Vapourer Moth caterpillar. Does anyone have any idea what it could be? There were no bushes around, just an abundance of heather, ling, cotton grass and some sundew plants.
Thanks