The commonest way to rid your house of them is to clean thoroughly with a very powerful hover and remove all sources of foodstuff they might eat. The uncommon but the surest way would be to burn your house to the ground as they do tend to exist in most habitation at a background level.
Super - bigger pictures reveal that these are larvae of Dermestes, prob D. ladarius or D. peruvianus. These are also in the family Dermestidae and the larvae feed on organic materials. In homes they tend to be associated with either very squalid conditions where you will be knee deep in abandoned and decaying foods (the kind of thing you see on TV Grime Busters programmes). Otherwise they are found in the cleanest of homes feeding on dead birds stuck up chimneys, dead rats/mice equally trapped somewhere or meaty dog biscuits. In most cases it turns out to be pet food.
Let us know if you find the source.
Now i'm confused. We've seen them in my son's bedroom. There has only been the odd one, on a few occasions.
We had the guttering, soffits and facia boards replaced with pvc, early last year, so we're pretty sure there is nothing dead in the loft - if there was, wouldn't we smell it ?
Could a beetle have got lodged onto my sons clothing and then found a dark corner to lay it's eggs ?
I really can't thinnk of any other way it could have got in.
In your first images it looked like the larva was tapering towards the end. Thus Attagenus. Your new images (congratulations to your clever way to get a new camera despite your wifes prior objections!) are definitely of a Dermestes sp. I hope you have them both!
The larder beetles (Dermestes) utilise quite a broad range of food, much of it not as smelly as a dead rat and much rather "insignificant". Almost any "dry stuff of animal origin" will do. See http://www.museumpests.net/pdfholder/38image.pdf.
Apart from being able to crawl through tiny spaces, the adult beetles can also fly and thus easily enter through for instance an open window. However, the adult beetle wouldn't lay eggs at random (there has to be something for its larvae to eat), and without the beetle having found a suitable place for its eggs there would be no larvae. Now, go look for that forgotten cheese sandwich under the bed!