If you’ve ever licked a slug, you may have noticed a strange numbing or tingling sensation in your mouth shortly after. This is caused by a slimy substance that slugs secrete to help them move and defend themselves. Here’s a closer look at why slug slime makes your tongue go numb.
Slug Slime Contains Anesthetic Properties
The main reason that slugs can create a numb feeling in your mouth is because their mucus contains chemicals that act as anesthetics. Many species of slugs and snails produce numbing mucus as a defense mechanism against predators trying to eat them.
The mucus contains special nerve-blocking substances that cause numbness and irritation when contacted. Some of the specific chemicals found in slug slime that contribute to its anesthetic effect include:
- Benzoquinones – naturally occurring anesthetic
- Glycoproteins – compounds that block nerve transmission
- Glycolipoprotein fluids – includes inflammatory lipids
When a slug secretes its slimy mucus coating, these anesthetic components transfer to whatever surface the slime touches. So when you lick a slug, those chemicals get onto your tongue, causing the numbness.
The Numbness is Temporary
Although having your tongue go numb after licking a slug can be an unsettling sensation, the effect is luckily short-lived. The mild anesthetic chemicals found in slug slime typically only cause numbness for about 10-15 minutes before sensation starts returning to normal.
The amounts of anesthetic substances transferred by licking are very low, so the numbing is localized to the tongue and mouth. Any weird mouth feelings should pass within half an hour at most.
Protective Adaptation in Slugs
The anesthetic properties of slug slime aren’t there just to surprise humans who decide to give the slimy creatures a lick. The numbness-inducing mucus actually serves a vital protective purpose for the slug.
By secreting numbing substances when threatened, slugs can temporarily paralyze the mouth and tongue of predators trying to eat them. This gives the slug a better chance to escape while the predator deals with mouth numbness.
So in a way, the bizarre sensation of getting your tongue numbed by slug goo is a small glimpse into the slug’s ingenious defenses!
Not All Slug Species Cause Numbness
While many slugs have anesthetic mucus, not all varieties produce strong enough secretions to numb human mouths. Licking some slug species may just leave a slime trail without triggering any numbness.
Some slugs known for their potent numbing slime include:
- Black keelback slug
- Brown slug
- Dusky slug
- Garden slug
- Leopard slug
Meanwhile, these species tend to have milder slime that likely won’t anesthetize your tongue:
- Banana slug
- Greenhouse slug
- Marsh slug
- Red triangle slug
Don’t Lick Unknown Slugs!
While a bit of slug slime likely won’t cause lasting harm, it’s still not a good idea to lick slugs at random. Some slugs and snails may harbor parasites like the rat lungworm, which can infect human brains and spinal cords if ingested.
Licking unknown slugs and snails outdoors comes with a small risk of accidental parasitic infection. The numbing or tingling sensation definitely isn’t worth picking up potentially dangerous parasites.
How Slugs Produce Numbing Slime
Slug mucus starts out as a thick, sticky substance produced by a gland in the slug’s body called the pedal gland. The pedal gland excretes several compounds that combine to form the slimy mucus.
Specific cells in the gland produce the anesthetic substances like benzoquinones and glycolipoproteins. These compounds are mixed in with the watery mucus as it leaves the pedal gland.
The resulting anesthetic mucus mixture helps the slug move around easily and defend itself if needed. All the slug has to do is secrete some of the numbing goo when it senses potential danger.
Pedal Gland Anatomy
In most slug species, the pedal gland consists of two large lobes located beneath the slug’s foot. These lobed glands make the anesthetic mucus components before releasing them through ducts.
The pedal gland produces fresh slug slime constantly to replace mucus as the slug moves around. This ensures the mucus stays slick and slippery at all times.
Slime Distribution
Slugs have a unique bodily motion that allows them to spread their numbing slime evenly as they travel. Rhythmic muscular contractions ripple along the slug’s underside from back to front.
This rippling motion spreads the pedal gland secretions over the entire mucus trail behind the slug. Spreading the anesthetic slime helps protect their path as they move.
Effects of Numbing Slug Slime on Humans
Aside from causing temporary tongue numbness, getting slug mucus in your mouth can also produce other effects including:
- Tingling or slight burning sensation
- Irritation and inflammation of the tongue/mouth
- Reduced bitterness sensitivity
- Altered sense of taste for a short time
- Possible allergic reaction depending on slug species
The effects of slug slime vary based on how much numbing mucus got into your mouth, as well as your individual sensitivity.
In most cases, the symptoms are mild and harmless. But if numbness persists more than an hour or other concerning reactions develop, you may want to contact your doctor.
Treating Numbness and Irritation
To helpmanage any discomfort from getting slug slime in your mouth:
- Rinse mouth thoroughly with water or saline solution
- Avoid irritating the area further while numb
- Use over-the-counter oral anesthetic if needed
- Take antihistamine if allergic-type reaction occurs
- Contact doctor if numbness exceeds 1-2 hours
The numbness should resolve on its own within 15-30 minutes. Try to resist the urge to keep licking or poking your numb tongue, as this may damage the tender tissue.
Why Might Someone Lick a Slug?
Licking slugs is generally not advised, even though a small lick likely won’t cause lasting harm. So why would someone voluntarily taste one of these slimy creatures?
Some reasons people may lick a slug include:
- On a dare from friends or as part of a prank
- As a risky teenage experiment
- From curiosity about the numb sensation
- For shock value or attention
- On accident by rubbing slug slime on mouth
Kids and teens are the most likely to try licking slugs on purpose for amusement. But plenty of daring adults have also sampled slug juices out of curiosity or drunken silliness.
Is Licking Slugs Safe?
Licking a slug isn’t extremely hazardous, but it does come with some risks, including:
- Potential infection from bacteria/parasites
- Allergic reaction in sensitive individuals
- Choking hazard from sucking up slime
- Extreme nausea/vomiting from taste
It’s impossible to tell just from looking if a slug carries dangerous microbes. So it’s better to simply avoid putting slugs in your mouth altogether.
Slug Slime Uses
While you shouldn’t ingest it, slug mucus does have some intriguing applications, including:
- Numbing agent in topical pain relief gels
- Active ingredient in skin care, especially anti-aging
- Preservative and antibiotic in some traditional medicines
- Component in products that repel insects
Researchers continue studying the bioactive compounds in slug slime for potential pharmaceutical and cosmetic benefits.
The Science Behind Slug Numbing Slime
Let’s take a closer look at the key scientific factors that give slugs their tongue-numbing powers:
Anesthetic Compounds
Specific molecules in slug mucus interact with nerves to block sensation. Local anesthetics like benzoquinones penetrate nerve cell membranes and interrupt the transmission of signals that communicate touch, temperature, and pain.
Glycoproteins may also contribute by binding to surface receptors on nerve cells and temporarily blocking conductance.
Rapid Absorption
The incredible stickiness of slug slime enables its bioactive compounds to rapidly transfer into mucous membranes. This allows the anesthetic chemicals to penetrate mouth and tongue tissues quickly.
The pedal gland secretions are also water-soluble, further increasing absorption speed.
High Potency
While the amount of numbing slime acquired from licking a slug is minuscule, the potency of the anesthetics makes the effects noticeable. Benzoquinones are hundreds of times more potent than compounds like lidocaine.
Just a few micrograms of slug anesthetics can create temporary numbness on human tongue and mouth tissue when applied directly.
Rapid Onset
After being absorbed into the tongue, the anesthetic actions of slug mucus also kick in very fast – normally within just 30-60 seconds. This quick onset results in a startling but short-lived numbness.
The numbness wears off quickly too as the natural slug anesthetics dilute in saliva and lose potency.
Key Takeaways
Here are the key points to remember about the strange numbing effect of slug slime:
- Slugs produce anesthetic mucus for defense that causes numbness in predators.
- Chemicals like benzoquinones are responsible for the numbing effect.
- The numb feeling if you lick a slug should resolve within 30 minutes.
- Not all slug species secrete mucus that can anesthetize human mouths.
- Try to avoid purposely licking slugs as they may carry parasites or bacteria.
While fascinating, slug mucus can also be dangerous if ingested. So if you get the urge to lick one of these slimy critters, you may want to think twice!
The curious sensation of oral numbness shows just how effective the slug’s protective slime really is.