What would happen if I let a leech leech?

May 31, 2016 2:01 PM

There are leeches in a pond near here. What would happen if, out of curiosity, I let a leech latch and lunch? Any significant danger to me or the leech?
posted by pracowity to Science & Nature (15 answers total)

My understanding from informally-acquired learning in outdoorsy contexts: though it's not common, leeches are a possible vector for blood parasites and other pathogens, and are thus best avoided when they're not sourced from a sterile environment. The leech would probably appreciate the meal, though.

That said, I am not a leech nor a parasite expert, so take my words with a grain of salt.
posted by BrandonW at 2:12 PM on May 31, 2016 [9 favorites]

To the leech, no. To you, possibly. There will be swelling and itching after the leech drops off (don't try to pull it off, it will barf on you), and the wounds tend to bleed a lot because leeches gift with with an anti-clotting agent to make their job easier. If you wash and dress the wound, infection is unlikely, and leeches do not generally transmit blood pathogens to humans. However, it is possible, and some people have allergic reactions to the bites, so I wouldn't court this as a fun activity or anything.
posted by ananci at 2:17 PM on May 31, 2016 [9 favorites]

It sort of depends on where you live and what type of leeches they are, but according to this PDF flyer from New Hampshire, you should be fine. And apparently some people are allergic to leeches so you want to watch out for an allergic reaction. Also, it is a myth that the bites don't hurt. (That last link is to a blog about leeches that is amazing, PS.)
posted by blnkfrnk at 2:42 PM on May 31, 2016 [3 favorites]

I was bitten by a leech long time ago in NJ. I didn't even notice it for quite a while (swimming and stomping around in a lake with a very muddy bottom). When it did come to my attention there was a short bout of screaming (I was a tween at the time), it was ripped off, and then the small bite bled for a while (see anti-coagulant in above comment). The bite shape was kind of cool, two concentric circles.

I did much better than the person who stepped on a rusty nail and had to get a tetnaus shot.
posted by brookeb at 3:01 PM on May 31, 2016 [5 favorites]

I use leeches for fishing and have had them stuck on me at various times - never an issue but like others said, they do tend to bleed so if your on any anticoagulants or anything like that, might want to check with a doctor first. I've always pulled them off, they are not very painful but are slimy so I can see where the ick factor comes in.

However, I'm more curious as to why you want to do this - is it simply for the experience?
posted by lpcxa0 at 3:36 PM on May 31, 2016 [2 favorites]

I once removed my shoes in a tropical rainforest in India to find my feet practically covered in leeches. Some had been smooshed into pulp inside my (wholly unsuitable for jungle hiking) sneakers, many I ripped off, but some I saw dropping out fat and happy. The bites bled dramatically, and later itched worse than gadfly bites. Other than that, nothing happened. Well, I may have cried a bit, because yuck.
posted by sively at 3:36 PM on May 31, 2016 [12 favorites]

If you find them on you quickly and they are not very big you can brush/flick them off with no pain/blood/itchiness/etc, or at least such has been my experience with Ontario leeches.

I just wanted to make a note re. disposal, though. One summer at the cottage I found one on me after going into some muck, and went tearing into the cottage to brush it off and into the toilet and flush sixty-three times. And he came back up! More flushing. Both times he went down, and both times he fairly quickly made it back to the toilet bowl (at this point typing this I involuntarily shuddered, even though this was 30+ years ago). I don't think anybody really objected too much to me using most of the box of salt on his last trip to the bowl. So. Yeah. Don't flush a live one.
posted by kmennie at 4:09 PM on May 31, 2016 [6 favorites]

From the blog linked to by blnkfrnk, which included a post about misinformation from "How Stuff Works". HSW's misinformation:

2) that leeches raised in captivity are "sterile to a certain degree" (all leeches, wild or farm raised harbour Aeromonas in their crop; a course of antibiotics is recommended during post-operative leech therapy)

So … maybe not a good idea?
posted by verschollen at 4:46 PM on May 31, 2016 [4 favorites]

BTW, medical leeches are used even today, in e.g. cosmetic surgery. And bloodletting by leeches is an ancient practice. But I have no doubt that there is a non-zero risk of infection if you get one directly from pond scum.
posted by sively at 4:47 PM on May 31, 2016 [1 favorite]

The Natural History Museum in Los Angeles has an annual "haunted museum" event every Halloween. I know that at least once one of the staff members attached a bunch of leeches to his face as a part of the event. So it seems like the blood sucking isn't a problem, but consider that those were laboratory leeches from a sterile environment. I wouldn't want pond leeches on me.
posted by Parasite Unseen at 4:49 PM on May 31, 2016 [2 favorites]

Folks have already addressed both the infection possibilities and the ickiness factor, so all I'll add is, you're not going to lose very much blood per leech, or even per dozen. And if you could stand to leave them alone, they'll drop off by themselves when they're full.
posted by easily confused at 6:07 PM on May 31, 2016 [1 favorite]

Leeches are gross, but as far as parasites go they're pretty harmless. Not a lot of damage, low risk of pathogens, and not painful. I prefer them over mosquitos; at least leeches don't fly around in my bedroom while I'm trying to sleep and make irritating noises in my ears.
posted by Anticipation Of A New Lover's Arrival, The at 6:15 PM on May 31, 2016 [2 favorites]

My grandfather owned a general store in the early 1900's and, according to my Father, kept a jar of leeches in a big jar on the counter to treat bruises. I got a black eye once and Dad was all set to go down to the local reservoir and get me a bucket of leeches...noooooooooo, Daddy, no!
posted by BoscosMom at 9:41 PM on May 31, 2016 [3 favorites]

Response by poster: However, I'm more curious as to why you want to do this - is it simply for the experience?

Just to see. I've had plenty of mosquito bites and tick bites and bee stings and so on, but these are the first leeches I've run into and they interest me. I like to watch creatures up close, and there's nothing closer than when one is feeding on you.

Judging by the above answers, I... just might let it happen the next time one tries. I probably won't go out of my way to arrange the thing, but if it happens I won't call the ambulance and the fire department and the army corps of leech removers.
posted by pracowity at 11:11 PM on May 31, 2016 [1 favorite]

If you really just want to check out some leeches at no risk to you, you can put some meat in a coffee can with holes in the lid, leave it in your body of water, and come back later. At that point you can pick a winner to try on your arm if you really want to, although they might be full from the meat.

Shoot, you got me wanting to hang out with leeches now.
posted by blnkfrnk at 5:32 AM on June 3, 2016