What arachnids are commonly called false scorpions?

The arachnids commonly called false scorpions are pseudoscorpions.

Pseudoscorpions are tiny members of the arachnid order Pseudoscorpiones. They look like miniature scorpions because they have broad, pincer-like pedipalps, but they lack the long segmented tail and stinger of true scorpions. Most are only a few millimetres long, making them easy to overlook in homes, leaf litter, soil, caves, and tree bark.

Despite their intimidating appearance, pseudoscorpions are generally harmless to people and can be beneficial predators. They feed on mites, booklice, carpet-beetle larvae, clothes-moth larvae, ants, and small flies. Some species practice phoresis, hitching rides on larger animals such as beetles or flies to disperse to new habitats.

The name “false scorpion” describes their appearance, not a close identity with true scorpions. Pseudoscorpions have eight legs and pincers, but their abdomen ends bluntly and they do not possess a venomous tail. Some species produce silk cocoons for mating, moulting, or surviving cold conditions.