“Where do the moth larvae come from?” asks this reader in his submission. “Why are they in my house?” He does not attach any photos to his submission, nor does he provide further context, so we do not know exactly which moth larvae he is dealing with. That said, we will nonetheless provide a brief overview of some of the moth larvae people typically find in their home and why and how they end up there. Moths are insects, and like any insect passes through three distinct stages of life: ‘larvahood’, pupation, and finally adulthood (when they have metamorphosed into a moth).
Like butterfly larvae, moth larvae are usually referred to as caterpillars, and it is not entirely uncommon to find them in one’s home. The main reason why moths are more likely to enter one’s home than butterflies is because there are more moth species that are attracted to light (such as the dagger moth), and this could be a reason why these particular larvae ended up in our reader’s home. Perhaps a pregnant dagger mother moth flew into our reader’s home and laid her eggs there, and then the larvae hatched and are not roaming about our reader’s home. Equally, a pregnant moth could have laid her eggs in the home for a different reason: because she was seeking a safe, dry space for her eggs to hatch and for her larvae to remain unbothered. Now, it will be quite obvious if the larvae in one’s home came from a batch of eggs that hatched inside: not only will they be very small and immature, but there will be a large population of them (such as in the photo below of a group of newly-hatched American ermine moth larvae). We do not know how many larvae our reader found, so we cannot say whether or not they hatched in his home.
So, with that in mind, there are other ways moth larvae find their way into people’s homes. It is possible to accidentally bring them indoors on one’s clothing or shoes, especially if one has been out in a forest, or somewhere populated with trees and/or bushes. Likewise, the caterpillars could simply crawl through an open window or door, or even through a tear in a window screen (which is why it is so important to make sure one’s window screens are intact!). Alternatively, we have recently heard from readers who describe larvae coming through their vents. One can prevent this by installing bug screens inside one’s vents.
Finally, the question of why they are inside his home depends on the species. As we said, the dagger moth would have laid her eggs in his home simply to seek shelter for them, so they could safely hatch with little disturbance. That said, a species like the webbing clothes moth would want her larvae in his home so they can feed on his textile items, such as carpets, clothing and upholstery. Similarly, a pantry moth would want to lay her eggs on food items in the kitchen and pantry, as that is the larvae’s primary source of sustenance. In any case, if our reader is finding a lot of larvae in his home, it would be a good idea to give his home a proper clean.
To conclude, this has been a brief look at how moth larvae enter people’s houses and why they would want to do that in the first place. We hope our reader finds this helpful, and we wish him the very best!
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