Arachnids are a class of joint-legged invertebrates that include creatures like spiders, scorpions, and ticks. They have eight legs, unlike insects, which have six. Arachnids are found in various habitats, from forests to deserts, and play important roles in ecosystems, such as controlling pest populations. Most arachnids are predators, using their specialized mouthparts to capture and consume prey. For example, spiders spin webs to trap insects, while scorpions use their stingers for defense and hunting. Despite their sometimes fearsome reputation, many arachnids are harmless and contribute to the balance of nature.