Large Yellow Underwing Moth Larva

I found this caterpillar in the dirt while I was weeding today.

I have to say that I've found these before and assumed they were some type of beetle larvae but I found this University of California webpage which explains the differences between various larvae. I now know to photograph larvae from their underside as well as from the top when possible.

So, from this photo, with its legs (and prolegs) in the air, it's obvious this was a caterpillar. I think it was just playing dead; I moved it to another area of dirt and then couldn't find it later (and I don't think a bird had eaten it in the meantime!!)

Next I had to post the photos to the Wild About Britain forum as I couldn't find a good id online. They got back to me within 30minutes to say it's the caterpillar of a Large Yellow Underwing moth - never would have guessed!