“I saw some of these worms in my cat’s fur, near his butt, but I’m not sure if it’s a parasite or just something from my garden”, writes Th?o in their submission regarding the black, worm-like organism pictured below. “It’s very small, like 5mm long, and very lithe. It’s a pinkish color (it looks darker in the picture). It also died (or dried out) soon after I found it, about 10-15 minutes later. We live in south east Asia, where there’s a tropical climate. Thank you for helping me.” To start with, we have to say that, whatever suggestions we make as to the worm’s identity, Th?o should take them with a grain of salt. The reason for this is that, since this worm was found on Th?o’s cat, it is possible that this is a medical situation.

“I found this in my swimming pool in Mobile, Alabama and I’m wondering if it’s a leech?”, asks Dean in his submission regarding the glossy, black, worm-like creature pictured below. Right off the bat, we have to agree with Dean that this does look like a leech. That said, when we zoomed in on the photo, we saw what looked like part of the creature’s underside, which was a lighter gray color. This made us think about slugs, and the possibility of this being one, though leeches also typically have lighter-colored undersides.

“Are these crane fly larvae, or horse-leeches?” asks Jonathan about the black, worm-like creature pictured below. “I’m in western NC. These guys are about a ¼-inch long. Closest I could find on my own research are the two stated above. Thank you for your time!” After doing some sleuthing of our own, we have always come to similar conclusions as Jonathan – this does resemble crane fly larvae somewhat (though this creature is a little darker than most crane fly larvae), and it does look like a horse leech (though not as slimy, but that could be due to drying out). In addition to these two creatures, we thought this looked like it could be a lugworm or a stick-resembling caterpillar such as the Geometer moth caterpillar.

“What is this worm?” asks this reader in his submission regarding the little, brownish worm pictured below. “Found among algae in the backyard koi pond in northern Illinois. Travels by attaching (perhaps by suction) one end and feeling around with the other. Can stretch to well over 4 times its resting length. Seeks air if submerged. Appears to be slightly flat. Was discovered clinging to hand. Found today. No discernible segmentation.” The thing that caught our eye in the excellent photo our reader sent in is the flattish part at one end of its body, which we assume to be its head. This is likely the part that it uses to “attach” itself to things and move along using, as our reader stated, “suction”. Based on this, as well as its appearance, we are inclined to say that this is likely a leech.

“Have recently found a very small” worm, states this reader in his submission regarding the “black, glossy” creatures pictured below. “Maximum size is three quarters of an inch, to an inch.”

“What is this?” asks this reader about the black organism in the screenshot below. The creature was found next to our reader’s car by dog excrement.

“I have an infestation of some kind which really affects me,” states this reader from Phoenix Arizona. She asks for our help in identifying anything from the photos she sent in.

“I found this on our water while I was filling the tub”, states this reader in her query concerning the black worm pictured below. She is not sure if they are leeches or something else, and wants to know if it is harmful.

There is no getting around that leeches get a bad reputation, and we are sure that a couple of our readers might even have grimaced at just reading the word. However, while movies and TV represent leeches through their parasitic relationship to humans, as an entity by themselves, leeches are quite fascinating, and can even be beneficial to humans!

A reader wonders if the creature in this photograph is a dead slug. From the photo we can tell that the creature has black coloration, a smooth exterior, a shape that is bulbous at the head but thins out towards the tail, and is small compared to the $10 bill our reader exhibited for size comparison.

Glossy, black worms were found by this reader in her bed sheets. Having recently moved to Florida, our reader wonders if this is something her dog or her landlord’s cats is bringing in to her home, and hopes that we can tell her what these creatures might be.

We believe the small black organisms our reader found in her pond are either leeches or black fly larvae. Both are similar in appearance, though leeches are slightly bigger, and both are commonly found in ponds. Neither species are considered invasive and neither should damage her pond or cause any problems with the fish!

We received a very interesting question from a reader in Germany about a worm that may have bitten her mother’s arm – or “sucked upon” her mother’s arm – while she slept. The reader referred to the worm as “limb boring,” which is fitting since the worm evidently did some damage to her mother’s arm, producing an open wound about the size of a 5 pence coin (which is about the size of a dime). The reader initially didn’t believe her mother, thinking she must be mistaken about what happened, but this Christmas she visited her mom, who showed her the scar from the worm bite. Moreover, the reader found a dried worm in a vent near her mother’s bedroom, and the vent was spattered with dry blood. The reader is now unsure what to think, and wrote to us to see if her mother’s story about the biting worm is at all possible.

A reader wrote to us about a rash her son has in response to what is believed to be a leech bite. She found what looked like a leech on her son’s PE kit after rugby practice, and it was at this time that she noticed his skin reaction, which began as a red spot, and then spread into an itchy rash that covered parts of his body, arms, and legs. The reader has already sought medical help, and her son has been prescribed antibiotics. She only wrote to us to ask if we have ever heard of this sort of skin reaction occurring in response to a leech bite, and also to determine if what she found was in fact a leech.

A reader wrote to us a few days ago about some small black worms she found at the bottom of her kids’ laundry basket. She also found a couple more worms when transferring their clothes from the washing machine to the drier, so the worms can evidently be traced back to the clothing of her children. The reader was wondering what these black worms in the laundry basket are, and we think they might be leeches (which are actually worms) or potentially slugs (which aren’t worms).

A reader sent us a picture of two smooth, black, worm-like creatures that he found by a swimming pool, which he thought might be leeches. The leeches, if they are leeches, were on a ledge right on the side of the pool, a little above the water line. They reader said they moved very slow by expanding and contracting, and that they are black on top, but a lighter, tan or brownish color on the bottom. The reader was only wondering if he found leeches, so we’ll limit ourselves to the matter of identification. Did our reader find leeches by the pool?

A little while back, we received a very detailed email from a reader about a worm, or what is believed to be a worm, that he encountered. The reader described his situation in some detail: he was sitting on his porch, which is enclosed by screens, when he felt as if he was being bitten on his arm. In response, he examined his arm and found what appeared to be a very small thread. However, the “thread” moved, becoming longer and then contracting again. Because of this movement, the reader concluded that he had come across an extremely small worm. Later, the reader found a few additional tiny worms on his arms and legs.