“Yesterday I found this little semi-transparent whitish worm with a darker end just outside of my bathtub”, writes Christina about the worm-like organism pictured below. “Today, I found two more in the tub and one on the ledge. I have no idea where they’re coming from but it’s hard to believe it’s from the drain because they are terrible at walking and climbing. They start to climb up and just roll down when the walls get too steep. They are small (about 2-3mm). I haven’t found them anywhere else inside or outside the house and there are no flying insects that I’m aware of. I live in Southeast Lower Michigan.”
To start with, we want to thank Christina for the ample context and great photos she sent in: they really help us identify the creatures we are asked about. When it comes to these critters in particular, there are a number of things they could be. Unfortunately, identifying semi-transparent worm-like organisms with black heads is difficult because many worm-like creatures share this exact description and look very much like the creatures Christina has been finding. With that said, there is one thing we are confident about, which is that this is an insect larva.
The most important difference between a worm and a larva is that, while a worm stays a worm for its entire life, a larva is just at the beginning stages of maturation, and will undergo a complete, physical transformation. For example, a caterpillar is just a butterfly/moth larva: it will eventually move into another stage of life called pupation, during which it begins its metamorphosis into a butterfly or moth. The same goes for most insects: they start as larvae (or really they start as eggs) before they become an insect. The larva Christina found could be a moth larva, a beetle larva, a fly larva, or even an ant larva. And all of these possibilities represent thousands of species within each category, making it all the more difficult to identify which specific species of insect Christina found.
With all of that said, there are still some things we can point out to her that might be helpful. For instance, regardless of the larvae’s lack of climbing abilities, they could still be coming from the drain if the mother insect laid her eggs in or around the drain. Likewise, the eggs could be somewhere on the wall or ceiling (often eggs are also translucent, or just really small, making them hard to see with the naked eye), and so the larvae are hatching from there. In any case, it seems like the source is the bathroom, so they must be coming from somewhere. What we recommend is that Christina simply move the larvae outside, and that she give her bathroom a proper clean, including her drains. She might want to search and clean the rest of her home, but as these little guys have been showing up only in her bathroom, we think she has managed to discover the source before the larvae infest the rest of her home.
To conclude, we are not entirely sure what species of larvae Christina found in her bathroom, as the possibilities are virtually endless. Typically, drain fly larvae infest people’s bathrooms, but not only do they not look like the larvae Christina found, but they are excellent at climbing walls. Despite not being able to provide a specific identification, we hope that we have managed to help Christina somewhat, and we wish her the very best!
All About Worms is always free, always reader-supported. Your tips via CashApp, Venmo, or Paypal are appreciated! Receipts will come from ISIPP Publishing.