Sarah Todd: Gnawing concerns about buying the best of British

The children have decided this one is probably a relation as it's been up to no good – eating the last remaining chocolate bar from their Christmas selection boxes – from the same hiding place.

"I thought mice were supposed to like cheese," said the disgruntled daughter, who had saved her favourite (a Flake bar) until last.

"And it's all daddy's fault," she continued. "If he hadn't been the sort of person who steals people's chocolate bars I wouldn't have had to hide it…"

Thankfully, now that her mother is on a diet she's above suspicion whenever any goodies go missing. There might have been a packet of crisps but, in mitigation, it was snowing and an instant energy boost was needed. And what brilliant crisps they were. They were Sainsbury's-own ready salted.

The store often gets on my nerves with the amount of Irish beef, New Zealand lamb and Danish bacon on its shelves. The crisps, in contrast, caught my eye as they had the Union Flag on the plain white packaging – boasting that they were from all-British potatoes.

It's interesting, as a fairly typical hassled working mother trying to do her bit in buying British, the knock-on effect that simple things like crisps can have. A little bit of research has shown that when Sainsbury's went all-British with its own-brand crisps it began buying an extra 2,000 tonnes of potatoes per year from our country's farmers. Until now it had never even crossed my mind that crisps might be made with foreign potatoes.

Our daughter has just finished reading an old copy of Black Beauty. In one line the horse complains about a highly-strung companion making his block bang on the tying-up ring. She didn't understand what the block was, so it was wonderful to be able to get out what – if I remember rightly – we always called a clog.

This one, pictured, was used in the olden days to tie-up cart horses in their stalls, then my mother's ponies, then mine and – the other day in an experiment – our daughter's old chap. Rather than a knot on the tie-up ring, threading the rope through and attaching the block of wood to the end allows the animal a lot more movement.

"The inside of it looks like somewhere a mouse ought to live," observed a certain small person.