Are millipedes toxic if eaten?

Millipedes are arthropods in the class Diplopoda, distinguished by having two pairs of jointed legs on most body segments. With over 10,000 described species, millipedes come in a wide variety of shapes and sizes. Many people are curious whether millipedes are poisonous or toxic if accidentally ingested by humans or pets.

Are millipedes toxic to humans?

The short answer is that most millipede species have some level of toxicity, but they are generally not dangerously poisonous to humans. Millipedes produce a variety of chemicals for defense, some of which can cause skin irritation, allergic reactions, or other adverse effects if ingested. However, serious illness or death from eating millipedes is very rare.

Millipede toxicity comes from benzoquinones, cyanide, and other defensive secretions produced in glands along the body. When threatened, millipedes can release these substances, which are meant to deter predators. The potency of millipede toxins varies by species. Some have very mild secretions, while others contain more powerful venom.

If a millipede is ingested, the main risks are:

  • Skin irritation – secretions may cause redness, rashes, blistering
  • Allergic reactions – swelling, difficulty breathing, anaphylaxis
  • Nausea, vomiting, diarrhea
  • Numbness, tingling around the mouth and lips

Serious effects like seizures, respiratory failure, or death are very uncommon but can happen in rare cases after eating highly toxic species. The venom acts mainly locally and does not spread through the body. Unless someone has an allergy, the worst symptoms usually resolve within a few hours. There are no documented cases of long-term effects or organ damage from millipede toxins.

As a general rule, most common household or backyard millipede species in places like North America and Europe have relatively mild venom and do not pose a major health risk if ingested. However, larger, exotic millipedes from tropical regions may contain much more potent chemical defenses and are best avoided.

Are millipedes toxic to pets?

Much like humans, millipede toxicity poses a low risk for dogs and cats in most cases. However, pets may be more vulnerable to adverse effects than people if they eat multiple millipedes or highly venomous exotic species.

Some potential risks of millipede ingestion in pets include:

  • Paw swelling, irritation if secretions contact skin
  • Excessive drooling or vomiting
  • Difficulty breathing if allergic reaction occurs
  • Loss of coordination, tremors or seizures (rare)

As millipedes are not part of a natural pet diet, consult a veterinarian if intentional ingestion occurs. With proper treatment, most pets recover fully. Try to prevent pets from preying on or intentionally eating millipedes. Seek immediate vet care if serious symptoms develop after exposure.

Overall though, the vast majority of common millipede species do not contain enough toxin to fatally harm dogs or cats when ingested. Monitor your pet closely after exposure just in case, but in most cases, effects are localized and not life-threatening.

What species of millipedes are most toxic?

While all millipedes produce some form of chemical defense secretion, species vary widely in toxicity. Some of the most toxic groups include:

  • Giant African millipedes – Among the largest millipede species, these can reach over 12 inches (30 cm) long. Their powerful toxins can blister skin and even kill small animals.
  • Guinea worms – A group of tropical millipedes known for producing cyanide alongside other venoms. Their toxins can be extremely potent.
  • Polyzonium millipedes – Widespread in Europe, these can release cyanide in high concentrations when threatened.
  • Spirobolida millipedes – An order of millipedes that includes the bumblebee millipede, named for its warning coloration. It secretes toxic benzoquinone.
  • Spirostreptida millipedes – One genus (Ityphilus) includes species with highly irritating secretions used for defense.

As a general rule, the largest species of millipedes from tropical climates tend to have the most powerful venom. Smaller, temperate species frequently have quite mild secretions. When identifying an unknown millipede, avoid handling it until you can determine if it is a toxic variety.

What toxins and chemicals do millipedes produce?

Millipedes utilize a diverse array of chemical secretions for defense. Some of the main toxins include:

  • Benzoquinones – Probably the most common millipede toxin, these organic compounds can irritate skin and eyes. Some may have antimicrobial properties.
  • Hydrogen cyanide – A potent poison that inhibits cellular respiration. Even small amounts of cyanide can be dangerous.
  • Alkaloids – Various alkaloid compounds have been isolated from millipedes. These may have neurotoxic effects.
  • Terpenes – Volatile organic chemicals found in plants and some millipedes. They often smell strongly and can deter predators.
  • Fatty acid secretions – Oily or waxy secretions that may cause skin irritation.
  • Phenols – Aromatic substances like tannins that have antimicrobial properties and may deter predators with their smell.

The specific cocktail of toxins varies between millipede orders and species. Research is still ongoing to fully characterize the diversity of millipede chemical defenses. The blend of toxins likely depends on each species’ particular ecological roles and predators.

How much millipede venom is dangerous to humans?

The threshold for dangerous or lethal effects depends on an individual’s size and sensitivity. As a general guideline:

  • For adults, ingesting or handling one or two small, common millipedes poses very little risk. Dozens may cause more severe effects like vomiting or seizures.
  • For children, even 1-2 millipedes could potentially trigger serious allergic reactions or toxins effects. They should not intentionally handle millipedes.
  • For highly toxic giant millipedes and similar species, venom from just one individual could potentially be life-threatening if ingested, especially for small children. These should be avoided.
  • For pets, the ingestion of more than 3-4 millipedes may require medical intervention depending on the size and species. Look for symptoms like drooling, dilated pupils, or trouble breathing.

Of course, these numbers are very general. The actual toxicity depends on many factors, including the species, size, individual variation, and personal sensitivities. Still, this provides a rough estimate of dangerous venom quantities from millipedes. A few common backyard millipedes likely pose minimal risks, but exotic tropical species can be far more toxic. When in doubt, exercise caution around unfamiliar millipedes.

What determines how toxic a millipede species is?

Several factors influence how potent and harmful a millipede’s venom might be:

  • Size – Larger millipede species tend to be more toxic than small ones. With more surface area, they can produce and store more toxins.
  • Habitat – Tropical species are often more toxic than temperate species. Millipedes from Africa, Southeast Asia and South America include some very venomous species.
  • Coloration – Bright warning colors like red, orange, yellow or purple can signal toxicity. Drab colored millipedes usually have milder venom.
  • Classification – Some taxonomic groups like Spirobolida tend to contain more toxic species on average.
  • Predators – Millipedes with dangerous predators like large mammals may evolve more potent chemical defenses.
  • Diet – Millipedes that feed on toxic plants may sequester those toxins and incorporate them into their own secretions.

In essence, millipedes from harsher environments with more pressure from predators tend to develop stronger venoms. Always exercise caution around large, colorful, unfamiliar species since these often signal enhanced toxicity.

What effects do millipede toxins have on the human body?

Millipede toxins affect people through two main mechanisms – general cytotoxicity and specific interference with biological processes:


Many millipede secretions are corrosive or irritating when they come in contact with skin, eyes, and mucous membranes. Some effects of this include:

  • Skin redness, blistering, peeling
  • Conjunctivitis if sprayed into the eyes
  • Burning, swelling, numbness around mouth and tongue
  • Coughing, pain if inhaled into lungs
  • Gastroenteritis – vomiting, diarrhea, abdominal pain if ingested

These effects are localized to the area of contact and mostly resolve once the toxins are removed or metabolized.

Specific toxin effects

Millipedes also produce toxins that interfere with biological processes:

  • Cyanide – prevents cellular oxygen uptake, potentially leading to asphyxiation
  • Alkaloids – may interfere with neurotransmission and cause paralysis
  • Benzoquinones – disrupt cellular metabolism

In extreme cases, specific toxins can trigger widespread symptoms like seizures, respiratory failure, kidney damage and death. However, these effects usually require ingestion of a large amount of pure toxins. Topical contact or swallowing a few millipedes is unlikely to cause severe systemic issues in most people.

The main take-away is that millipede venom causes localized irritation rather than body-wide organ damage or death. But caution is still warranted, especially around unfamiliar tropical species. Seek medical care if concerning symptoms develop after handling or eating millipedes.

What should you do if you ingest millipede venom?

Stay calm, as severe reactions are uncommon. Follow these steps to treat millipede venom ingestion:

  1. Rinse out mouth and lips with plenty of water if toxins were swallowed. Spit out the water.
  2. Wash skin that contacted secretions with soap and water to prevent further absorption.
  3. Call poison control or a doctor if symptoms like numbness, drooling, difficulty breathing, vomiting, or blurred vision develop.
  4. If prescribed, take antihistamines or corticosteroids to reduce allergic reactions.
  5. Drink plenty of water to dilute and excrete toxins.
  6. Seek immediate medical attention if rapid heartbeat, severe difficult breathing, seizures, or loss of consciousness occur.

Most mild cases can be treated with supportive care at home. If unsure, call poison control or consult a doctor regarding your symptoms. Millipede venom ingestion can be alarming, but try to remain calm and take steps to wash away and dilute the toxins.

How do you avoid accidental millipede ingestion?

Here are some tips to steer clear of accidentally swallowing or handling millipedes:

  • Supervise small children and pets when outdoors around piles of leaves, compost, rotting logs and other places millipedes congregate.
  • Wear gloves when moving debris or gardening where millipedes may live.
  • Shake out shoes before putting them on to avoid stepped-on millipedes.
  • Clean up any millipedes found indoors to prevent encounters.
  • Avoid placing hands in mouth after handling soil or unknown objects outside.
  • Carefully inspect produce grown in gardens where millipedes are present.
  • Use caution when lifting logs or rocks where millipedes may shelter.

Look before picking up debris from the ground. If millipedes are discovered indoors, use gloves or tools to remove them. Supervise kids and pets outdoors in millipede-prone areas. With some basic precautions, accidental ingestion is usually avoidable.

Key Points

  • Most millipedes have some level of toxicity but are not dangerously venomous to humans in most cases.
  • Millipede venom can irritate skin, eyes, and mucous membranes. Ingestion may cause gastrointestinal effects.
  • Very rarely, highly toxic species may cause severe allergic reactions, seizures, respiratory issues or death.
  • Larger, tropical millipedes tend to be more toxic than smaller, temperate species.
  • Immediately wash off any millipede secretions on skin. Seek medical care if concerning symptoms develop after exposure.
  • Supervise children and pets around yards and gardens where millipedes are active to prevent ingestion.


Ingestion of millipedes does pose some risks from their toxic secretions, especially for small children. However, the majority of common backyard millipedes have only mildly irritating venom. Serious effects are infrequent and deaths are extremely rare from the amounts involved in most accidental exposures. Exercise some reasonable precautions, but also understand that the risks are low with the millipedes you are most likely to encounter. Seek medical advice if significant symptoms develop after contact with or swallowing millipedes.

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