Is it correct that "bugs" lie dormant in flour and if the flour is kept too warm that these "bugs" come to life and live in and around the flour? My daughter and her friend were helping me make plum and apple crumble, they were in charge of the crumble. I had help until they found that the flour was "walking". I tried to explain these "bugs", but not sure of the true story behind this. I bought a new bag of flour and they continued with their crumble. The apples and plums were grown in my own garden, picked fresh and the girls made the most crunchiest crumble I have tasted - better than my own (always use the Be-Ro book recipe). It was devine, no "bugs" mentioned at the table!!
You can get weevils in flour ..specially if it is kept in a warm place or not been used for a while.That's not to say you have done that though !!!
I usually decant flour into an airtight container and only buy enough for what I need at one go .
There is some info here http://www.hintsandthings.co.uk/kennel/problem .htm
Scroll down a bit. Glad the crumble was nice though !!