What is the adaptation of arachnids?

The class Arachnida includes eight-legged organisms like spiders and scorpions. They have adapted to live on land by developing a covering which serves as a flexible exoskeleton. This exoskeleton conserves water and is effective in providing protection from the arachnids environment. They have an internal method of sexual reproduction, with spiders having internal chambers for their young spiders. Most arachnids digest their food by pouring digestive juices over it, then ingesting the liquefied remains back...

The class Arachnida includes eight-legged organisms like spiders and scorpions. They have adapted to live on land by developing a covering which serves as a flexible exoskeleton. This exoskeleton conserves water and is effective in providing protection from the arachnids environment. They have an internal method of sexual reproduction, with spiders having internal chambers for their young spiders. Most arachnids digest their food by pouring digestive juices over it, then ingesting the liquefied remains back into their system. Most arachnids live in humid, moist areas, and are nocturnal, which means they are sensitive to light, so they are most active at night when the sun goes down. Some arachnids immobilize their food by poisonous bite, such as the Black Widow spider or the scorpion.