I feel sorry for him because he is a drinker moth caterpillar so-called because they drink from droplets of rain water or dew. So what do they do when it does not rain and there is no dew? This one is nearly fully grown and so will turn into a pupae very soon and then hopefully survive the winter to hatch out next year into a big brown moth….called a Drinker moth surprise surprise.
You can see what the moth looks like (nothing special) and get more info on this species by visiting http://www.uksafari.com/drinkermoth.htm For more info on insects and wildlife in general have a look at my page on wildlife called in this blog which is called. Animals in Poitou-Charentes.