To cut a long story short: Effin carpet beetles! In multiple places!
At least we think they are, so far we have tried these ways of killing them
- squashing them (but there's hundreds of the shites)
- fly spray (the web says forget it)
- hoovering them up throwing alcohol on them, throw match and whoosh
- drowning in aforesaid alcohol *
- carpet bombing

with Nippon powder
Any other wisdoms? Hanging is of course far too good for them.
Oh there is also the worry that they were first found under some artefact brought back from 2010s holiday so we may have started the biggest eco disaster to hit the UK since that dodgy curry last December. Please do not tell the eco Rozzers.
*
Panic not, no JD or Vodka has been wasted as I seem to have 5 litres of neat eco-alcohol bought to fuel some whim