Where do flour grubs come from.

[DXP55]

Monday the wife opened as new bag of flour and inside was a load of very small grub/maggots. - We have had them before but were do they come from. This was a unopened packet and it was stored in a air tight plastic container so I am hoping they were in the flour to start with.
I can't ever remember seeing them in anything else - not even pasta.
Talking to a guy in supermarket and he bought a very large sack of dog food (breeder) and when he opened it it was riddled and they had spread all round his pantry - Dog food maker paid for the clean up.

Any ideas - I could google it but wanted real live reports.

 

[DXP55]

Our flour is stored in cupboards in the kitchen - we are not posh enough to have a pantry.

This was a fairly new packet - probably purchased at start of lockdown. We don't use it much.

ps. by the way you could see them crawling about.

 

[DXP55]

it's not always posh to have one

Tongue in cheek my friend

Did a bit of googling and you can put it in freezer forever providing its in a air tight container - you can then defrost it and keep it in fridge.
This will be our new way of keeping flour - good job we don't use much as there isn't a lot of room in freezer.

I have a feeling we downsized too much.