Heterometrus spp.

About Heterometrus

Heterometrus is a genus of large forest scorpions native to tropical and subtropical Asia, from India through Southeast Asia. Several species are sold in the pet trade — often under vague labels like "Asian forest scorpion" — including H. longimanus, H. spinifer, and H. petersii. Exact species identification can be difficult without examining the trichobothrial patterns on the pedipalps.

These are arachnids (Order Scorpiones), not insects. Like all scorpions they are venomous, but Heterometrus species have large, powerful pincers and a relatively thin tail — a reliable indicator of mild venom. A sting is comparable to a bee sting for most people: painful but not medically significant unless you have an allergy.

Heterometrus species are frequently recommended as an alternative to the emperor scorpion (Pandinus imperator), which is restricted under CITES Appendix II. Care requirements are very similar, and Asian forest scorpions are generally more available and less expensive.

Enclosure

A 45×30×30 cm enclosure suits a single adult. These are forest-floor burrowers, so floor space is more important than height.

• Substrate: 10–15 cm of damp coconut fibre or organic topsoil for burrowing
• Hides: cork bark, half-logs, or similar dark retreats. Scorpions are nocturnal and will be stressed without secure daytime cover
• A shallow, stable water dish — scorpions drink regularly
• Mist every 1–2 days to maintain humidity at 70–85%

Temperature & lighting

Keep temperatures between 24–28°C. A heat mat attached to the side of the enclosure (not underneath — deep substrate over an under-tank heater can trap lethal heat) provides a gentle warm zone. Always use a thermostat.

No special lighting is needed. These are nocturnal animals and bright light is stressful. Like all scorpions, Heterometrus fluoresces under UV light due to compounds in the exoskeleton — a UV torch is useful for locating them at night but should not be left on.

Feeding

• Crickets, dubia roaches, locusts, and mealworms are all accepted
• Feed 2–3 prey items once or twice per week
• Prey should be no wider than the scorpion's body
• Remove uneaten food within 24 hours to prevent mould and harassment during moults

Asian forest scorpions are enthusiastic feeders and will often seize prey with their pincers alone, barely using their stinger — a behaviour consistent with species that rely on mechanical strength rather than venom.

Cohabitation & breeding

Heterometrus species can be kept communally under the same conditions as emperor scorpions: introduce all individuals to a new enclosure at the same time, provide plenty of hides, and ensure adequate space. Cannibalism remains a risk if conditions are crowded or food is scarce.

Females are viviparous — they give live birth after a long gestation. Newborn scorplings climb onto the mother's back and remain there until after their first moult. Separate the mother from other adults during this period to prevent the young from being eaten.

Handling & temperament

Asian forest scorpions are generally docile but tend to be slightly more defensive than emperor scorpions. They may adopt a threat posture (raising their pincers and tail) more readily. Despite this, they rarely sting — like the emperor, they rely primarily on their large, powerful pincers rather than venom.

If you choose to handle, let the scorpion walk onto your hand rather than picking it up. Move slowly and calmly. Handle over a soft surface at a low height. Never grab or restrain the scorpion — a pinch from the pedipalps is more likely than a sting, but neither is pleasant.

If you get stung

• Clean the area with soap and water
• Apply a cold compress to reduce swelling
• Pain is typically comparable to a bee sting and subsides within a few hours
• Seek medical attention if you experience difficulty breathing, significant swelling beyond the sting site, or any signs of an allergic reaction
• If you have a known allergy to bee/wasp stings, exercise extra caution