spider

Spiders are arachnids of the order Araneae. They are characterized by eight legs, two main body segments, and the absence of wings. The adult body consists of a cephalothorax (prosoma) and an abdomen (opisthosoma). Most spiders produce silk from spinnerets and use it for a variety of purposes, including building retreats and catching prey.

Spiders possess venom glands connected to fang-like chelicerae that inject venom to immobilize or predigest prey. Visual ability varies; many species rely on vibration, texture, and web movement rather than sight. Respiratory structures also vary, with some species using book lungs, and others having a tracheal system.

Silk is a protein thread extruded from spinnerets and hardened by air. It serves many roles: nets and orb webs to capture prey, egg sacs to protect eggs, draglines for safety lines, and shelters. Silk production is widespread among spiders, though patterns and uses differ widely.

In behavior and ecology, most spiders are solitary and territorial. They occupy a wide range of habitats, from forests to deserts and human dwellings. Diet consists primarily of insects and other arthropods. Some actively hunt, while others rely on webs or ambush to trap prey.

Reproduction and life cycle: Mating often involves courtship rituals. Females may lay eggs in silk sacs; males may transfer sperm via specialized organs. Many species hatch as spiderlings and undergo several molts before reaching maturity; lifespans range from about one year to over a decade in some larger species.

Interaction with humans: Spiders are important natural pest controllers. Some bites can cause medical symptoms, though serious reactions are rare. Spider venoms and silk have inspired materials research. Conservation concerns include habitat loss and decline of prey availability in some regions.