Amblypygids are flattened, tropical or subtropical arachnids, well designed to creep beneath tree bark and stones where they hide during the day, emerging at night to hunt. Not only are they flat, but they also have extremely long legs, especially the first pair which are not used in locomotion. These fine, multi-segmented appendages are sensory organs and function like the antennae of insects. Several species live in dark caves, making these 'antennae' particularly useful. When walking, amblypgids resemble crabs, moving more side-ways than forward. Despite their clumsy appearance they can be very fast. Prey is captured using large spiny pedipalps armed with small pincers. It is then rapidly moved to the moderately sized chelicerae where it is torn open to receive digestive juices.
From six to sixty eggs are produced by the female. As in some other arachnid groups, she carries them around attached to her body after she lays them. A parchment-like material is produced to hold them to her underside. Within this they hatch and moult before she releases them.