I found tens of these tiny millipedes in a rotting apple amongst a pile of damp leaf litter on the ground. This picture of one on my thumb shows just how small it is – only about 15mm long. You can tell it's a millipede because it has two pairs of legs per body segment. Centipedes have just one – and are generally much flatter.
I initially assumed that this was a baby and would grow into a larger, darker millipede, having not seen this cream with red spots version before. However a bit of internet research shows that this is the full-size Spotted snake millipede (Blaniulus guttulatus) which is apparently very common but not often seen since it's small and lives in the soil.

Well spotted Sam3, I have been searching the net for ages for info on these. My garden in S Norfolk UK is overrun with them, they can destroy my onion, potato and strawberry crops and who knows what else,but what is the answer to them. Thank you, if you read this.
Geoff
I didn’t realise they were a pest until I read your comment. I found some info to back up your assertion though:
http://www.allotments4all.co.uk/smf/index.php?topic=55043.0
According to this post (http://www.the-piedpiper.co.uk/th11b.htm -about halfway down) they tend to follow up on damage caused by other pests, but also eat root crops in periods of drought as a source of moisture. I’m not sure what to suggest.
I think these are killing my onions too. Am going to try some nemotode treatment (Steinernema Feltiae, read an article from US stating in had shown some success.