Dark gray ceiling spots turn out to be eggs/larvae?

Question: Hi- at my wit's end, because never had this problem before... 21 year old house in generally good/clean condition, although do have several closets with very old clothes that have not seen use for several years... (probably in retrospect a bad idea). However, up until recently, no signs of infestation. About 1 week ago, saw dark gray "spot" (kind of crescent shape, maybe 2" length) suddenly appear above master bedroom shower stall. Assumed it was ceiling paint flaking off... This morning, saw exact same spot (size and color) appear quite far away, on ceiling in home office (same upper floor of house). When I checked shower stall today, that spot had "disappeared" overnight! But what I then saw is that in shower stall base, there were dozens of tiny caterpillars crawling around, about 3 mm long and 0.5 mm wide, black head, clear body. I vacuumed off the "spot" in the office, and I wiped the residue with a strong cleaning wipe, saw the same caterpillars. Have also cleaned/disinfected shower stall, vacuumed there... I will check, but I have not seen, in the clothes I actively use, any damage signs, nor any flying moths. What have  I got? Thank you.

responder: An Ask Extension Expert Replied September 04, 2024, 2:07 PM EDT
response: Thanks for the interesting question.  I don't yet have an answer for you.  I do have a question.  Has there been any evidence of crawling things in your home office? Thanks

responder: An Ask Extension Expert Replied September 04, 2024, 2:28 PM EDT
response: Thanks for your question and patience. In reading your question again, I note that you had seen these crawling creatures in your office as well. I’m afraid that at this time, I can’t help you. When I try to enlarge the pictures, I end up with images that lack resolution and clarity. Without being able to identify things, I really can’t suggest any remedial procedures. What you have done so far makes sense. If these things continue to appear, you probably should contact a professional exterminator and obtain his/her opinion. Also should they reappear, try to get some pictures of higher resolution. Sorry about not being able to help you. Thanks for consulting our forum.

responder: The Question Asker Replied September 04, 2024, 2:48 PM EDT
response: Hello, Thank you very much for your reply! To be clear, the ones in the office were not yet at the “crawling” stage. They were in the stage of being in a gray “spot” (agglomeration) on the ceiling. I think what happened in the shower stall is that they reached maturity and dropped down? i.e. they ended up on shower stall floor, at which point they became crawling… Here is an enlarged crop of the creatures’ I swabbed up from the shower stall, on a cleaning wipe:For scale, those are curled gloved fingers on the right. Thank you again!  Peter  From: ask=<personal data hidden> On Behalf Of Ask ExtensionSent: Wednesday, September 4, 2024 1:07 PMTo: Peter Mach Subject: Re: Dark gray ceiling spots turn out to be eggs/larvae? (#0153956)

responder: The Question Asker Replied September 04, 2024, 2:48 PM EDT
response: Hello, Apologies, I just replied to an earlier note, with an attempt at improved image. I realize it is still not ideal. Just from the fact that these spots/agglomerations appeared on the ceiling, does that make any pest/moth type more or less likely? Thanks again! Peter   From: ask=<personal data hidden> On Behalf Of Ask ExtensionSent: Wednesday, September 4, 2024 1:28 PMTo: Peter Mach Subject: Re: Dark gray ceiling spots turn out to be eggs/larvae? (#0153956)

responder: An Ask Extension Expert Replied September 04, 2024, 4:12 PM EDT
response: Thanks for your response. Unfortunately the latest pictures still are not adequate for me to make an identification. Let me continue working with you and perhaps an answer can be reached: 1). I assume that the ceilings in the bathroom and the office consist of some rather impervious material. If so, it would be hard to understand how anything could be coming down through the ceilings. Still, what is above the ceilings in both rooms?  Water pipes? 2). Have you recently had any construction in your house? More specifically, have any lumber or wood products been brought in? What about firewood? 3). Have you recently brought in any plant material (e.g., plants) or fresh produce into your house?  4). Is your kitchen in proximity to the bathroom and office (I’m thinking of stored grain products nearby)? 5).  How do you know that the crawling critters have any relationship to the spots on the ceiling?  I assume that when you first these crawling things, the ceiling spots also disappeared.  Could these two things just be coincidental? 6). Do a little experiment. If you see these crawling things again, gently scoop up a few, put in a loosely covered container, and place in a location not exposed to direct sunlight. If we’re lucky, these critters will enlarge and perhaps transform into something more distinct and recognizable. Maybe a better picture could then be obtained.  In answer to your question, I would say moths would be the least likely candidate. Thanks much.

responder: The Question Asker Replied September 04, 2024, 4:30 PM EDT
response: I continue to be very grateful for your time! I understand that an accurate diagnosis requires accurate/good quality documenting material. I apologize for the photos, best I could do this morning while also dealing with the overall situation itself . To your questions: Yes, in both cases, it’s a drywall (sheetrock) “popcorn” sprayed ceiling, above shower stall and in home office. There is a shower head in the stall, but it is wall mounted, so actually, I don’t think there is a water line in the ceiling there. There’s a light fixture, though, embedded in the ceiling in the stall (recessed bulb). The “spot” (I am now thinking of it as an egg agglomeration) was nearby to that. Again, spot was about 2” in lateral extent, from far away it appeared gray. In the office, there is no water line or light in the ceiling, where I found the similar “spot” this morning.Actually, no construction. Construction is planned (kitchen remodel) but not started yet. No firewood (that’s the easiest answer I can give you out of all the questions: no wood fireplace).No new plants or plant material brought in. Limited amount of produce (regular groceries) although primarily it’s bagged/boxed pre-washed salad, and a lot of various kinds of berries (e.g. the boxed kind from Costco). That being said, the kitchen and pantry (and fridge) are one floor down from these events, i.e. this has been taking place on our top floor, whereas the kitchen etc. is the main floor street level.I think addressed in (3). There is a whole floor’s worth of separation, staircase, etc. What there is a lot of, on the floor where this has happened, is clothing… including several closets that have the long-unused clothing. There is a master bedroom closet not far from the bathroom, that has such clothing. And there is a closet in the office, although that one has clothing which is more actively used (and all maintained well/dry-cleaned). Not sure how relevant, but I’ll add that the house is fully wall to wall carpeted, on all levels (except hardwood floor in kitchen and tiles in the bathroom).Good question! It could be coincidental, but seems just very tied together. Last night, the “gray spot” was still there, above the shower stall. This morning, it was “gone”. And a new similar spot was in the office, easily 40 feet away (as the crow flies), in different room. I rechecked the shower stall and found the floor covered with the micro-caterpillars, so I assumed they dropped down from the stall ceiling. And as I said, when I vacuumed and wiped down the “spot” in the office, I saw the same kind of little caterpillars (but I am thinking those were not quite activated yet).Will do! Peter Mach From: ask=<personal data hidden> On Behalf Of Ask ExtensionSent: Wednesday, September 4, 2024 3:12 PMTo: Peter Mach Subject: Re: Dark gray ceiling spots turn out to be eggs/larvae? (#0153956)

responder: An Ask Extension Expert Replied September 04, 2024, 9:06 PM EDT
response: Sounds like a plan.  I think that the most important thing is to look for a recurrence of these events.  If nothing further happens in the next month or so, then they were isolated events.  If things recur, we'll have to continue and explore things. Good luck.  Thanks for consulting our forum.