This brought back horrific memories.......
A few years ago, I opened a packet of semolina and saw it 'move'. As did the all the flours and sugars, and all manner of dry goods..........
I even unscrewed the lid of a jar of sugar (with a guest standing my my side. I did the best Oscar performance of normality that one can imagine) to find a larvae happily crawling around the lid. It stopped in amazement at being found and looked expectantly up at me. It had, however, to go........
It turned out that we had been infested with 'product stored moths', probably brought in to the house in the semolina as it was the most heavily infested (it was heaving!) but they had quickly spread everywhere, as other Gransnetters have said.
A day or so later, I went into my utility room (having asked friends of mine if they were having a particularly bad year for moths, as I had noticed a few around) and there was, at the far end, a 'cloud' of moths.
As I stood, trying to comprehend what I was seeing, this 'cloud' moved silently towards me. They were coming to get me! Have you ever thought of malevolent moths? Well, I have seen them!
Fly spray? Poof. They brushed it off and kept on a-coming. In desperation I flew upstairs and grabbed my hairspray and used a whole can. That did the trick and they were no more.
I will never forget all the food we had to throw away and the hours of scrubbing and extra (unwanted!) cleaning, too.
Horrible, horrible, horrible. (The moths and the extra cleaning!)