Eggs and Larvae on Window

Share the knowledge

We just received some fantastic photographs from one of our readers. She found several hundred tan eggs on her window. They eggs darkened, and then hatched into larvae. The pictures she sent us are a great sequence displaying this process. Our reader is curious what kind of creatures these are. Here are the photos:

The eggs are very small, circular, and tan colored. The larvae are also quite tiny, have black heads, and dark colored bodies. We are confident that these are some type of larvae, but we aren’t entirely sure what kind of larvae. We think they are probably moth fly larvae. We have written about moth fly larvae appearing in large groups on walls before. These small larvae feed on decaying matter, and sometimes appear in large groups where other bugs have been killed. Adult moths lay their eggs on whatever their larvae will eat, so that when they hatch they can just start eating. So, if another bug was killed against the window, its remains could be serving as a food source for these larvae.  For example, maybe our reader swatted another bug against the window where these eggs and larvae appeared.

There are a few things we don’t know about the situation. These clues might be helpful in coming up with a more solid identification, or explanation for the presence of these worm-like organisms on the window. For example, how much time passed between the first photograph showing the tan eggs and the third photograph showing the larvae. Also, was this on the inside of the window or on the outside? We think probably the inside because you can see a green background that looks like it might be trees outside.

To conclude, a reader discovered some eggs and subsequent larvae on her window. We believe these are probably moth fly larvae. We recommend she clean her window to get rid of whatever potential food source is on it!


All About Worms is always free, always reader-supported. Your tips via CashApp, Venmo, or Paypal are appreciated! Receipts will come from ISIPP Publishing.

CashApp us Square Cash app link

Venmo us Venmo link

Paypal us Paypal link

Note: Some links on this site are partner links. That means that we earn a tiny bit if you purchase something through them, at no extra charge to you. This helps offset the cost of keeping this resource free for everybody (it doesn't cover our costs, but every little bit helps! :~) )
Eggs and Larvae on Window
Article Name
Eggs and Larvae on Window
A reader discovered some eggs and subsequent larvae on her window. We believe these are probably moth fly larvae.

Share the knowledge

Author: Worm Researcher Dori

4 thoughts on “Eggs and Larvae on Window

  1. @tristan – a moth laid its eggs in my window last night (light late on).
    Should I try to move eggs to a plant ?

  2. @tristan – a moth laid its eggs in my window last night, as I had light late on. Should I try to move eggs to a plant ?

  3. I’m wondering what exaclty it is laying the eggs.. there’s a cluster on my boyfriend’s passenger door.. I feel like the comment added could be wrong though. His truck sits in the dark in our driveway. The eggs weren’t there yesterday but we’re there today. They came up over night . I feel it’s very possible there was already a bug killed on the side of his truck that may have lead the moth to lay the eggs. That sounds more plausible than it being attracted to the light. At least in our case. I would love to know exactly what it is laying these eggs though.

  4. This is wrong; the moth laid its eggs on the window because it was confused by the light shining through the window at night and could no longer navigate its way to lay its eggs on the plants its caterpillars actually need to eat.

Leave a Reply

Your email address will not be published.