Identify It > Invertebrates Section > Harvestmen >
Scientific name: Opiliones
Size: Body 5 to 8mm. Legs up to 50mm long
Distribution: Common throughout the UK
Months seen: April to October
Habitat: Low vegetation and damp moss in woods, fields and gardens. Often found under outdoor window ledges.
Food: Small insects, vegetation and bird droppings
Special features: It's difficult to describe harvestmen without making comparisons to spiders. Harvestmen do look like spiders. They have eight legs, two palps, and like spiders they are carnivorous, but the similarities end there. Harvestmen don't spin webs and they don't produce venom.
If you look at the main body at the centre of all those dangly legs you'll notice that it's all one piece.
Spiders have two parts to their bodies - a cephalothorax (head and thorax) and the abdomen. In the harvestmen these two parts are fused together as one.
These creatures are known as 'opiliones', and there are over twenty different species living in the U.K. Most of them are only active at night.
Many have a bump on top of the head which houses their two eyes. This is called an 'ocularium'.
Their second pair of legs is slightly longer than the other three pairs. These legs are used as sensory organs to feel their surroundings. They are constantly in motion as the creature moves, tapping all around, in a similar fashion to a blind person using a stick.
When attacked, harvestmen are able to shed a leg as a defensive trick. Even after the leg becomes detached from the body it continues to jump and flick about. This distracts the predator while the harvestman makes its escape. They are able to shed up to four legs in this way, but they need to retain at least one of the sensory legs to survive.