a plastic bag may be enough, as they are hatching already and frost may only delay that process. After catching a few I'd check what they are and find the source.

They might be food moth larvae, I'd check all packages with rice, grain products etc...the larvae can gnaw through surprisingly thick plastic and start weaving threads like the stuff spider webs are made of. Often that is the only giveaway, a bundle of spider web threads in the top of a bag or bottle.

I like the image of using a vibrating sex toy to coax insects out of a coffee grinder.

Maybe I am a little squeamish? I think that even if I could kill them and then run a bunch of coffee through, every time I raised a cup to my lips I'd think about the remaining decaying insect debris wedged in crevices inside the grinder. It would, umm, bug me.

jpender wrote:I like the image of using a vibrating sex toy to coax insects out of a coffee grinder.

If OP does, he should film it for TikTok and watch the coffee world melt down, thinking they're out of the loop on some super clever new distribution trick

Freezing might work but many insects in egg state can survive very cold temperatures. Liquified gasses can generally disrupt cell function but most home appliances cannot attain the level of cold required to ensure a 100% kill.

I do suspect there could be issues regarding heat and lubricants but the processing plants I worked in were required to use food grade lubricants which are not known for being high temp tolerant. Those lubes were actually consumable in reasonable quantities (incidental) and the worst they would do is cause gastric distress. As suggested by HB an oven at lowest temp is unlikely to cause issues and particularly if you do not leave it turned on for extended periods. i.e.: preheat the oven before putting the grinder in and then manually cycle the oven to keep the temp up as needed to get the internals of the grinder to 140º and hold it there for several hours. The "warmer" cycle of an oven if manually attended should get the job done. You really don't have anything to lose if the bugs are keeping you from using the grinder.

Another probably untenable option would be to have a commercial exterminator to use phosgene or similar "killer" gas and seal the grinder for a period in excess of the hatch time of the egg maturity cycle. This is also a 100% kill and requires no further cleaning other than purging the machine of residual carcasses and egg casings as the gases leave no surface contamination. The downside of this choice is expense.

mborkow wrote:Just a little extra protein in your coffee :D

People often say that about insects, that they aren't harmful, possibly even nutritionally beneficial, and that people are just squeamish about them. And for farm grown insects I would agree with that (but still not want to eat them). Wild insects on the other hand could have been all sorts of places before landing in one's food. Maybe the risk isn't enormous but one could probably lick the inside of their trash can without negative consequences. Most of the time.

Is there likely to be free-range lube within the casing? Sealed bearings are fine at 140°; heating bearings to 200°or more, to accommodate install on a shaft, is pretty standard.

You've got an immune system. Use it!