Image: Scorpion

Scorpion

Scorpion, line drawing.

Creator:
Andrew Howells
Rights:
© Australian Museum

Notes

Scorpions are common arachnids found in gardens and forests throughout Australia. They are found under logs, rocks and in shallow burrows in earth banks. There are also desert species that construct deep spiral burrows in desert sand. Scorpions are mostly nocturnal but they can be active during the day, especially during prolonged wet weather. Scorpions tend to be larger and more venomous in the northern parts of Australia. The largest Australian scorpions can grow to 12 cm long, but many forest dwellers are only small.

Identifying features

Size:
  • 9 mm - 210 mm in length.
Body:
  • No constriction between cephalothorax (front portion containing head) and the abdomen.
  • Abdomen is segmented, cigar-shaped to tear-drop-like, with narrow tail.
  • Body appears hard.
  • Pectines (a sensory organ) present on underside of body behind legs.
Antennae:
  • Absent.
Eyes:
  • Up to 12 simple eyes, two found centrally the remainder on the front margins of cephalothorax.
Mouthparts:
  • For mushing and chopping up prey and slurping liquids.
Wings:
  • Absent.
Limbs:
  • Eight legs.
  • Pedipalps (appendages between first legs and mouthparts) are large with pincers (chela) at their ends.
Abdomen tip:
  • Long tail with sting at tip.

Where are scorpions found?

  • On land in many habitats including deserts.
  • Under rocks, logs and bark.
  • In burrows, especially desert dwelling scorpions.

What do scorpions do?

  • They are commonly solitary, few found in groups.
  • When disturbed they run under cover, or raise pincers and mobilise tail.
  • They are venomous. The venom is delivered via their tail and is used to paralyse or kill prey. Few are harmful to humans.
  • All scorpions are predators feeding mostly on other invertebrates but have been known to snare small vertebrates such as lizards. They use their pincers to clasp prey, then repeatedly sting the held victim, once paralysed the victim is liquefied with digestive juices.
  • They move with their pincers stretched out in front and the tail outstretched behind.
  • They are active at night or if active during the day generally in dark places; detectable at night with ultraviolet light.

What looks similar?

  • Pseudoscorpions are easily distinguished from scorpions as they are smaller than 10 mm in length and lack a tail.

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Tags scorpions, invertebrates, identification, BugWise, arthropods, arachnids,