Pseudoscorpions

As the weather warms up, more insects fly inside the house attracted to the light. Last night a small crane-fly came indoors, carrying two hitchhikers....

These are Pseudoscorpions, tiny arachnids which resemble tail-less scorpions. There are around 27 species in the UK and many of these are widespread and fairly common - but very rarely seen due to their minute size!
Most Pseudoscorpions live in leaf litter, or beneath loose bark where they search for even smaller invertebrates to eat, including springtails, mites, and small insect larvae. They are completely harmless to humans, but can inject their prey with venom from their claws. Some species are found in old book collections where they specialise in feeding on booklice.

The crane-fly who carried the passengers.

Pseudoscorpions commonly attach themselves to flying insects - for a free ride to new feeding territory, which also exposes them to new potential mates from other bloodlines. I have previously found some larger species attached to larger crane-flies, so perhaps these are a choice mode of transport when they emerge from their pupa in the soil.

Photo to show size, body length just under 2mm

Male and female Pseudoscorpions perform a 'dance' to start the mating ritual, I think that was going on with these two, although they soon separated and walked away from each other.

Pseudoscorpion dance