# 12 Amazing Facts About the Slow Loris, the World's Only Venomous Primate

*South and Southeast Asia · JUN 20 2026*

> Slow lorises are small nocturnal primates of South and Southeast Asia and the only known venomous primates; there are around nine species, every one threatened with extinction and protected from international trade under CITES Appendix I.

From a venomous bite to those enormous night-vision eyes, here are 12 surprising, science-backed facts about one of the planet's most trafficked primates.

## What are the key takeaways from this briefing?
- Slow lorises are the only known venomous primates, producing a two-part venom from a gland near the elbow.
- The 'arms raised' pose seen in viral videos is a fear response, not enjoyment.
- There are about nine species — eight in Nycticebus plus the pygmy slow loris, reclassified as Xanthonycticebus in 2022.
- Every assessed species is declining and threatened, from Vulnerable to Critically Endangered (IUCN).
- All slow lorises have been on CITES Appendix I since 2007, banning commercial international trade.

## Meet the slow loris: small, slow, and astonishingly strange

Slow lorises are small, big-eyed primates that move through the night-time canopies of South and Southeast Asia with a deliberate, hand-over-hand crawl. Cute as they look in viral clips, the reality of their biology — and their plight — is far more remarkable, and far more troubling. Here are twelve things worth knowing, every one of them grounded in the science.

### 1. They are the only venomous primates on Earth

No other primate produces venom. A slow loris draws a secretion from a gland near its elbow, mixes it with saliva, and can deliver a bite toxic enough to cause severe reactions in people.

### 2. The venom comes from the elbow

The brachial gland on the inside of each arm produces an oily secretion. When a loris licks it, the two-part venom is armed and ready in the mouth.

### 3. Raised arms mean fear, not joy

The famous "arms up" pose shared as a tickle reaction is actually a defensive posture — the animal is reaching for its venom gland because it feels threatened.

### 4. There are around nine species

Eight sit in the genus *Nycticebus*, and in 2022 the pygmy slow loris was moved into its own genus, *Xanthonycticebus pygmaeus*.

### 5. They are not monkeys

Slow lorises are strepsirrhine primates — closer kin to lemurs and bushbabies than to monkeys.

### 6. Their eyes glow in torchlight

A reflective layer behind the retina, the tapetum lucidum, amplifies dim light and shines back at a flashlight — which is exactly how poachers freeze them at night.

### 7. They are gum specialists

Tree gum and sap form a major part of the diet, supplemented with nectar, fruit, insects and the occasional small vertebrate. This makes them exudativores and notoriously hard to feed in captivity.

### 8. They move in slow motion for a reason

Their unhurried, non-leaping climb helps them stay invisible to predators in the dark.

### 9. Mothers "paint" their babies with venom

Females coat their infants in the gland secretion, an apparent deterrent to predators while the young are parked on branches.

### 10. They can live around two decades in care

Lifespans of up to roughly 20 years have been recorded in human care, with the pygmy slow loris averaging around 17.

### 11. Every species is threatened

According to the IUCN Red List, all assessed slow lorises are declining — ranging from Vulnerable to Critically Endangered.

### 12. International trade has been banned since 2007

All slow lorises sit on CITES Appendix I, so commercial international trade is illegal. Read the full [slow loris species guide](/wildlife-guides/slow-loris/) for the complete conservation picture.

WARN's partners in Indonesia and Malaysia care for confiscated lorises through months of dental treatment and dietary recovery. If these animals move you, a quiet way to help is the [slow loris appeal](/appeals/slow-loris/).

**[Read the full Slow loris wildlife guide](/wildlife-guides/slow-loris/)** for the facts, IUCN status and conservation context — or **[donate to WARN](/donate/)** to help fund the local partners protecting this species.

## What do people ask about this briefing?
### What is the most surprising fact about slow lorises?
They are the only primates known to be venomous. A slow loris produces an oily secretion from a gland near its elbow, mixes it with saliva by licking, and can deliver a bite venomous enough to cause severe allergic reactions, including anaphylactic shock, in humans.

### Why do slow lorises raise their arms?
Raising the arms is a defensive move, not a sign of pleasure. The animal is reaching toward the venom gland on its inner arm to arm a defensive bite. In viral 'tickling' videos, the loris is frightened, and its wide eyes are open because bright light is painful for a nocturnal animal.

### How many species of slow loris are there?
Most current sources recognise about nine species: eight in the genus Nycticebus, plus the pygmy slow loris, which was moved to its own genus, Xanthonycticebus, in 2022.

## Which sources does this briefing use?
- [Smithsonian's National Zoo — Pygmy slow loris](https://nationalzoo.si.edu/animals/pygmy-slow-loris)
- [IUCN Red List — Javan slow loris (Nycticebus javanicus)](https://www.iucnredlist.org/species/39761/179045340)
- [Nekaris et al. 2013 — Biochemistry, ecology and evolution of slow loris venom (PMC3852360)](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3852360/)
- [CITES — Appendices (Nycticebus, Appendix I)](https://cites.org/eng/app/appendices.php)

Human-readable page: https://worldanimalrescuenetwork.org/newsroom/slow-loris-12-amazing-facts/