A woman in the United Kingdom has written to us with a rather odd query. She has found something that may be a larva in her flat (apartment). The little critter is about 1/2″ (~13mm) long and seems to be leaking red liquid. In fact, it has stained our reader’s carpet. She would like us to tell her what it might be. She has attached the following picture:
It is difficult to tell from the photograph what sort of critter this might be. However, there are very few worms or larva that ooze any kind of blood or other red liquid. Our blood is red because it contains hemoglobin. According to the UCSB ScienceLine website:
Hemoglobin is a protein that forms a complex with iron molecules and together they transport oxygen molecules throughout the body. Iron has the property of reflecting red light and because there is so much iron in our blood, blood looks red.
Most worms and larva do not have hemoglobin in their bodies, so they never produce anything that looks like blood. One exception is the aptly named “bloodworm” (genus Glycera). These carnivorous bristle worms have a fluid that does have hemoglobin and is, therefore, red in color.
However, the picture our reader sent to us does not look like a bristle worm. Also, it is unlikely that a bloodworm, which is a marine animal, would just appear in her apartment. They are commonly used as fishing bait and to feed aquarium fish, so are sometimes brought inside on purpose. We suspect, however, that our reader would have known if that sort of thing was going on.
Leeches, which consume mammalian blood, can ooze their prey’s blood when injured. But the picture she has sent us does not look like a leech.
Given the information we have, we cannot name the species of the critter pictured. She does not say whether she actually saw the little fellow in her picture moving or not. If not, then it is possible that this is not a worm or larva at all. It could be a bit of animal material that was dragged into the house. If the reader has cats, it could even be a bit of a mouse left over from that day’s hunt. There are also some plants and trees that have red saps, and a bit of one of those could have been drug inside on someone’s clothes.
We are sorry we could not help this reader identify this animal (if it is an animal). If she has seen more of them, or has more pictures of this one, then we will be happy to take another look.