Carpet beetles! I hate 'em! I had never heard of them until the 70s, when we started finding holes in our socks etc. I found a little hairy thing in the sock drawer and put it in a jar and took it into the local council here in England. The pest officer (yes, there is such a public official here!) took one look and said: 'This is a woolly bear, the larvae of a carpet beetle.'
That was the start of our war on carpet beetles. He said they probably came down from the loft (attic space under the roof), possibly from a bird's nest, but there was no nest up there. We had our house fumigated, which was a horrible experience, and it did not work anyway. We were free of the pests for awhile, but then found a beetle on a windowsill one day, and knew they were back again.
I used to control them with Vapona, hanging Vapona in every wardrobe every spring, and putting a couple of them up in the attic space. That worked, but then Vapona was banned.
One year we lived in a house with a wooden fence at the back. I happened to look one day behind the grass at the bottom of the fence and, to my horror, there were tens of thousands of carpet beetles - all along the base of the fence, about 30ft long. I got the bug spray and sprayed all along the fence, but there are millions of such fences in England. Almost every back yard has such a fence.
Over the years we were free of the nasty little beasties off and on, but now we have had two beetles appear on a windowsill, alive and kicking (though not for long). Yuck, here we go again.
Just had a quick look at the web to see what other people are doing, and the bloggers suggest Borax and cedar wood in cupboards. Now I think about it....My Dad built a cedar closet in our house in America, a wardrobe lined with cedar wood where all the winter coats and wool clothes were kept during the spring and summer, and it worked. It also smelled wonderful. We never got holes in our clothes.
Mom, like every other American woman who married in the 1940s, had a large 'cedar chest,' a big blanket box made of cedar wood, and all sorts of things went in there. Never any holes. Time to transplant these ideas to the UK!
Also, of course, she was a real home-maker, a stay-at-home Mom, and our house was really clean. She did not have a lot, but what she had was very well looked after! I don't even know if America has carpet beetles, but they would not have lasted long in her house.
The other thing is...window screens! Why oh why do British builders not put screens on the windows? No house I have ever seen in England, Wales or Scotland has screens on the windows. Stupid or what? Welcome bugs, just come in. Crawl in, fly in, right this way! Carpet beetles, spiders, flies, mosquitoes, come on in! The only way you can keep them out is to keep the windows shut. Personally, I like to have windows open, but then you have to put up with a certain amount of six or eight legged critters. You cannot install your own screens because the windows are almost all casement windows which open outwards. Hardly anyone builds a house with sash windows that slide up and down. And even if they do, they do not leave fittings for screens. Ok, end of rant about British windows.
Here is a link to the life cycle of carpet beetles:
And here are some blogs about how to get rid of them: