They just are there–in the five pound bag of flour you just brought home yesterday. There, in the mixing bowl that was going to hold the biscuits for dinner, but now, in a puff of white smoke, ground grains with tiny hard beetles go into the burn pit out back.
But don’t blame the insects. They are just doing what they do to make a living, wingless though they are. They have learned to hitch-hike around the world over the past few thousand years as post-glacial humankind cultivated the land, then stored, then globally-shipped wheat products everywhere.
Read the details at NPR, and just go ahead and enjoy a little crunch in your next batch of pancakes.