[ That is one bug that I OTE]
Check around, under sinks, behind refrigerator, any open spot in any wall. Use the foam in can to fill it or putty or caulking. Well, this is just a guess and may be wrong.
I think they may come in from the sewer and into the sink drain plumbing. Reason for this, the "young uns" have shown up in and around sinks at night and in the shower if you can believe it. We have had about 6+ in two years. Hard to catch, well, we use the small vacuum with the hose and the crevice tool one person starts the vacuum and the other gets them out of the hiding place, it works good and the vacuum tube ride is a dead end. And, another item, when we go for awhile, I put bleach in the sinks and in the shower drain, about 1/4 cup and it does seem to work. Be sure to put the plug or stopper in the Disposal and the sinks. It has helped a lot.
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