A reader located in Indiana recently reached out to us about a worm found on her hand. After killing the first of its kind, an identical worm was found a few hours later. The worm appears minuscule in size and transparent in color, with a black inside.
It was not long ago we covered flea larvae, but we believe that that is what this creature is. Its physical characteristics justify this identification, though naturally we can never be 100% certain about anything. Flea larvae are born at a length of 2mm, but can grow up to 5mm before they move on to their pupal stage (the stage of growth before its fully-grown form). Given the size of the larva in the photo below, where our reader kindly offered a size comparison to her finger, we would guess that it is newly hatched. Once they have hatched, flea larva will search for food, their diet including: dead insects, faeces, and vegetables. Therefore, it was probably by mistake that this larva ended up on our reader’s hand. Additionally, flea larvae are blind from birth and tend to stray from sunlit places, thus preferring dark and damp locations to settle.
Fully-grown fleas are parasites. They feed on the blood of their prey by crawling on their skin and sinking their teeth into its flesh to drink. The most commonly found fleas in the home are cat fleas, which will feed on cats or dogs. Fleas that feed on human blood (pulex irritans) are not common in developed countries, but will also feed on pigs. If our reader lives on a farm, then this may be a possibility, but it would still be very uncommon to find them indoors. For this reason, the flea larva our reader has found is most likely one that would not feed on human blood.
At the same time, the fact that our reader has found more than one within the span of a few hours is concerning. Fleas are pests, and infestations can occur, even if one does not own any pets! We recommend that our reader check all of the places in their home that may match the description of where flea larvae thrive. Locations they can be found include: under carpets, inside bedding, underneath furniture, and in cracks and crevices in one’s home. If our reader discovers an infestation, we recommend vacuuming up the fleas rather than using any form of insecticide. However, if our reader is not confident in her abilities to ensure that these fleas do not pester her any further, then we recommend contacting a professional who is capable of handling this issue.
Lastly, in the rare case that this turns out to be a human flea (pulex irritans) and our reader becomes concerned about being a victim to this parasite, we recommend getting in touch with a medical professional and/or a parasite specialist to receive proper diagnosis and treatment. As we are not medical professionals, this is unfortunately not an area in which we can provide aid. Furthermore, if our reader has pets, we recommend taking them to a vet as soon as possible to check for fleas. There may be methods of checking and treating this at home, but just as we are not medical professionals for humans, neither are we for animals, so that is also not a field we can provide accurate diagnoses or treatment in.
To conclude, the tiny, clear worms our reader in Indiana found were flea larvae. While they can be harmful to cats, dogs and potentially other pets, there is a slim chance that the larva our reader found is harmful to humans. Nonetheless, infestations can occur, so in the case that there is one, we recommend our reader thoroughly cleans her house or that she contacts a professional!