right. DDs to school, then back home for a concerted deep-clean of the house. I found 3 websites last night helpfully saying threadworms are due to poor hygeine and shoddy housemanship (thanks for the judgement, chaps) and another three saying it's just due to little people an the visceral beings they are with nosepicking etc. all of them recommended scrubbing, hoovering and washing everything. Sigh. Have already done 3 loads of washing.
And phoned someone we visited ten days ago to warn them to keep an eye out to be told "oh yes, we've just had them...." sigh. That's probably the source then. Glamorous or what.