Weevil eggs, aka grain bugs, are in all bags of malt. To eliminate or kill them would require expensive and/or chemical treatment of the grain that you really don't want. The eggs will not hatch if the grain stays cool. I have heard below 74°, but I don't know that number to be accurate. If they hatch, purging the container with CO2 will kill them, although it usually requires several treatments. In the end, RDWHAB, as they won't affect your beer. As Mary Ann Gruber, the retired head maltster for Briess once said, "Grain bugs do not contribute significantly to chill haze."