I try to watch out for things like this, because I don't like loosing the food, not to mention the grossness, but the bag wasn't expired (according its date it was supposed to be good good until well into 2014), and the black beetles weren't particularly visible against the dark green mung beans, so from a cursory look at the drawer nothing seemed amiss. The first thing that looked odd was that there seemed to be more crumbly/dusty bits in the bag when I took it out, but it took me opening the thing and noticing the movement to connect the dots, i.e. that the crumbly bits were due to gnawing. At least the beetles stayed in the bag, rather than flying out at me or something.