Feeding Frenzy: Case Bearing Moth Larvae eat dog biscuit

Subject: What’s my bug?!
Location: Irvine, California 92612
February 17, 2011 6:34 pm
Living in Southern California. Have searched and searched and can’t find anything resembling there. They have a papery outer shell, and the head protrudes by only a couple of mm.. These pictures are of them feeding off a dog biscuit – when I’ve left one they turn up within an hour from under the baseboard. This is the most so far (16). They are mobile but very slow as the head / thorax comes out and drags the rest of the papery shell along.
Signature: Many thanks, Toby

Case Bearing Moth Larvae

Hi Toby,
Your image of an infestation of Case Bearing Moth Larvae has us aghast.  We have never seen documentation of so many in one place at one time.  Most identification quests for this cosmopolitan Household Intruder are of single individuals.  They feed on organic debris including shed pet hair.


Hi Daniel, thank you so much for getting back to me.  This is very interesting.
From what I can gather from the internet they’re pretty harmless, so I’ll leave them be for now.  Incidentally I tried them on a Lucky Charm but they seem to prefer the dog biscuit..  I think I’ve seen a maximum of 20 at one time, there are 16 in the pic I sent you.  Note also in the pic that there’s one emerging from the baseboard at the top, as well as a juvenile in the lower left.  Right now there are also a couple more making their way towards the biscuit across the bathroom floor, but they still have a yard or so to go.
Interesting also that they are _very_ alert – any motion around them and they go hide in their casings for a good 10 minutes.
Many thanks again, Toby.

Thanks for the update Toby.  We really enjoyed your observational account of the behavior of Case Bearing Moth Larvae.

Update:  July 26, 2014
Hi Dan,
Hope you’re well.
We’re very slowing relocating from Irvine to Utah.  The house here in CA is empty now and I’m slowly doing a final clear out and tidy up.
I’ve noticed a couple more Case Bearing Moth Larvae roaming around in the same area that I’d seen them back in 2011. I think I’ve seen the odd one in the years since then but infrequently and I’ve not really gone looking for them..
I’ve offered the obligatory dog biscuit so I’ll leave it for a day or so and see who turns up.
Thanks! Toby

22 thoughts on “Feeding Frenzy: Case Bearing Moth Larvae eat dog biscuit”

  1. If you think this is amazing, you should see my bunny’s hutch! Today I’ve collected close to a hundred of them. They just keep coming back. The area is mostly free of spiderwebs and other contaminants casebearers would be interested in. Let me know if you want me to take pictures. Tonight I caught a bunch of them writhing on the walls. It was shocking as from my observation, they’re sedentary in the daytime.

  2. I get these as well. I have a small dog, I have spider webs (what home does not over time) and I live in SoCal. Started noticing them a few years back. I can pick up about 5-8 a day and see them on floors, wall, even celling. We are extremely clean people, like OCD clean, but I don’t think they care since they eat at a micro sized level they eat stuff we don’t even see. I toss them in the toilet to drown them. Creepy bugs pulling themselves around by tongues it what it seems like.

  3. How do I get rid of these disgusting case bearing moths? I find them every day and just today I picked one up with a strand of my hair hanging from its casing. Will they bite humans or pets? Do they cause any medical harm to people or animals?

  4. I have some bugs similar to moth larvae they move from side to side. At first it was in the bathroom walls obviously they must flies, but I don’t see wings lately I found a few in the kitchen area, I don’t have pets and I live in Florida. I would like to know how to get rid of them any suggestions? today I sprinkled boric acid inside and outside the house I hope it would work.

  5. Hi- Just found some clothing moths recently. Going through laundry and am finding the case bearing moth larvae but with no heads sticking out, thank god. They seem empty. Is that possible?
    So am getting rid of them…does that help? Cannot use anything toxic here…for me and my two older cats. Cannot see any eggs or larvae. Feeling a bit overwhelmed…hardwood floors in whole condo and read I have to vaccuum between all floorboards in entire place???? Do not have enough time nor the money to hire someone….very overwhelmed right now. Have not seen more than a few moths in last few days…does that just mean they’re hibernating/growing?
    Please help….thanks.

  6. I live in Brisbane, Queensland Australia and have found a few of them around the house before. The first time I noticed one, I thought I was going mad seeing this spec of dirt moving (it was late at night). After closer inspection, the little cute worm face showed itself to try crawl off the paper I put him on.
    ~Would you guys know what they eventually turn into (ie. type of moth)? Would you be able to share a picture, and discuss their average life cycle term?

  7. My guess is they are fish moths. Have a lot of them crawling up my wall from a previously damp base board. They eat through clothing. Nasty buggers.

  8. im really freaking out now. i have seen these things in the house for awhile now. and i think they are the reason when i get bitten at night? i do not see the actual bugs that bite me but i can feel them crawling. i have welts right after.
    i can also feel them crawling on my clothes–but i dont see them on clothes.
    i only see the cocoon like thing like the one shown in the pictures. most of these things that i saw dont move. they are just hanging on the wall. under the table. the bunk above mine.

    i got bit a lot before (when i did not notice these things above my bunk). after i noticed those things, i did not get bit as much. but i still get bit.

    when i spray store-bought insecticides, they will become more active and will bite me more than ever. welts all over my body.

    do you guys get bitten?

    help me please. how do i get rid of these?

  9. Hi
    Don’t worry; case bearing clothes moths don’t bite. I have thousands, I found them living in the carpet underlay when i moved into my rented room. They eat their way up through the carpet and turn into little brown moths. I think they’re cute- whats not to love about a caterpillar that knits it’s own sleeping bag? They are completely harmless, but they will eat holes in your favourite woollens.

  10. First noticed these as a kid, called them tubeworms, watched one pulling itself by its mouth until it hit the wall. It stuck it’s head back in,there was some slight movement inside, then the head stuck out of the back side and it started moving along again, very cute. The moths themselves are also very cute, lhey like to sit on my arms, legs and ereader. I remember one hot summer when I had a fan blowing on me and a really big moth landed on my knee and turned his face into the breeze antenna streaming back like a dog with his out the car window. They don’t land on the rest of the family, so maybe I just taste or smell good to them, new moths jump and fly around me like I’m a jungle gym I don’t mind, I love animals, and they’re entertaining.

  11. Thank goodness I haven’t killed any of them. Poor lil’ critters, I think I’ll try leaving out a dog biscuit for all their hard work. They are so cute now that I know they are not blood thirsty parasites.

  12. I live in San Diego and found many cocoons in my kitchen cabinet – some that only store dishes. I have found them near my washer and dryer. Then when I pulled my stove out to clean it the cocoons were everywhere….maybe 100. They usually hang down from where they’ve attached in tiny spaces and when I saw the cocoons I figured the moth had already left – I had no idea about case moths that started with a worm that drags it’s cocoon around. The cocoons seem very flat. and papery. I have the small moths flying around which I want to get rid of. I also have cats. I don’t want these moths in the house because I’m concerned they will eat into my clothes and live in my closet. I vacuumed many of the cocoons. If they are eating cat hair they are probably living in the garage also and I will never get rid of them. I don’t know where these came from because in my entire life this is my first experience with them and my husband has never seen them before either..


Leave a Comment