Tailless Whip Scorpion

Paraphrynus mexicanus

Tailless Whip Scorpion

Paraphrynus mexicanus

Harmless

Not dangerous

Harmless, and not marginally. It has no venom glands, no sting and no tail. The spined front limbs are for catching insects and cannot meaningfully injure a person. It looks like the most dangerous thing on this site and is one of the safest.

SizeBody 15–30 mm; leg span up to about 150 mm

MarkingsEight legs, but the first pair is enormously long and thin, used as feelers rather than for walking · Flattened body with no tail and no sting of any kind

WhereCaves, rock crevices, under bark and debris in warm dry country. Strictly nocturnal.

How to tell it apart

Eight legs, but the first pair is enormously long and thin, used as feelers rather than for walking
Flattened body with no tail and no sting of any kind
Spined pedipalps folded in front like a mantis's forelegs
Walks sideways, crab-fashion, pressed flat against a surface
Body 15–30 mm, with a leg span several times that

Where you’ll find it

The desert southwest — Arizona, New Mexico, west Texas — and south into Mexico. Related species occur through the tropics.

Caves, rock crevices, under bark and debris in warm dry country. Strictly nocturnal.

How it behaves

The whole animal is built around touch. The first pair of legs is modified into whip-like antenniform feelers, sometimes several times the body length, waved constantly to map the surroundings in complete darkness. Prey is located that way and seized with the spined pedipalps. It is startlingly fast sideways and its instinct on being uncovered is to flee, not to confront. Some species show genuine maternal care and even social recognition between individuals, which is unusual among arachnids.

You’ve found one indoors

Nothing. If one is in a garage or outbuilding in the southwest, it is eating crickets and cockroaches and can be left or moved with a container. There is no reason to kill one and nothing to protect yourself from.

Common questions

Is a tailless whip scorpion venomous?

No, and not in the qualified way that phrase usually means. It has no venom glands at all — nothing to inject, and no apparatus to inject it with.

Can it sting or bite me?

It has no sting. Very large tropical individuals can pinch with the spined pedipalps if grabbed, which can scratch. That is the extent of the risk.

Is it a spider or a scorpion?

Neither. It is an amblypygid — its own order of arachnid, distinct from both, and distinct again from the whip scorpion, which does have a tail.

What are the two long front legs for?

Sensing. They are not walking legs; they are feelers, waved to map the environment in the dark and locate prey by touch.

Commonly confused with

Whip Scorpion Harmless

Keep identifying

Identify another animal from a photo or return to the Other guide.

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Where this was checked

iNaturalist — Paraphrynus mexicanus checked 2026-07-30

Last reviewed 2026-07-30. We identify, we don’t diagnose — what we can and can’t tell you.