Oriental cockroach, but we'll see what others think.

Yeah, I'd have to agree that looks very much like a female Oriental cockroach, Blatta orientalis.

Male oriental roaches have large wingpads but are also flightless. Orientals tend to inhabit sewers and plumbing, so they are difficult to get rid of completely and permanently. I wouldn't pour anything caustic down the drains. Do continue using the sticky boards if they work for you. You can also investigate baits containing boric acid, the one poison roaches can't detect before they ingest. Boric acid baits are essentially non-toxic to anything else, but take awhile to have an effect (you don't see dead roaches immediately). I can attest to the fact the effects are nearly permanent, though, whereas that is not the case with chemical treatments. Good luck.

Thanks very much for the quick feedback. You folks are great. Just in the past week or two the town ripped up street and replaced water pipe(s) right in front of this house and neighbor's. I wonder if that work "disturbed" the little beasts, since we hadn't seem them all winter (I've been here since Nov, 06). A note on behavior: one or two of my sticky traps seem to catch the most specimins. Got, like, 6 on the trap behind fridge. As if, one gets caught, screams for help, and his buddies get caught coming to the rescue. Or maybe, they're programmed to move similarly when emerging -- (i) crawl against gravity to a level place, (ii) proceed horizontally till hit a vertical, (iii) turn left/right keep crawling, then wham, there's the trap. Another theory that hit me: they're "smelling" their brethren, and following the trail. Noticed the caught ones are discharging some tiny (1/16') black pellets while on the trap. Eggs? Thanks again.