Can anyone identify these caterpillers or grubs?

[Tim Ingram]

Just looked again with my wife at these larvae and realised that I had misread the scale - they are only about half the size or less than swift moth caterpillars. I can't find a reference to the Bee Moth in my Collins Field Guides to caterpillars and insects of Britain - does this mean they are very uncommon?

[Margaret]

I'm not sure, Tim. I've certainly never seen anything like it before. It is the cacoons that are so extraordinary. See photo in the Natural History Museum's fact sheet. I don't like the idea of them eating the bumblebees which I see going into that box in the summer but maybe it's best just to let nature look after itself.

Afraid I had to delete the attachment because it was too large. Type Aphomia sociella into the Natural History Museum search box to read their pdf.

 Edit by maggi :  Here is the link to the NHM file : 
http://www.nhm.ac.uk/natureplus/servlet/JiveServlet/download/17033-6080/ID%2520sheet%2520007%2520Aphomia%2520sociella.pdf&sa=U&ei=oyPYUo3uNoeetAaX-YAg&ved=0CAUQFjAA&client=internal-uds-cse&usg=AFQjCNG2Mcv18IllpO42KCH1BCvSavqvGw

[Anthony Darby]

It's in "Collins Guide to Wildlife in House and Home".

[Margaret]

Thank you for sorting me out, Maggi!

[Maggi Young]

You're welcome, Margaret - I tried to reduce the size of the pdf but in the end it was easier to just add the link.

P.S. I had mistaken the size of the critters too -  as I discovered when I read Tim's comment and went back for a better look. 

[mark smyth]

This moth and its caterpillars live in my shed and are usually found under boxes - or maybe its a similar moth/caterpillar

[Margaret]

It means you have lots of bees, Mark, which must be good.