Flexi Says: Spiders produce silk threads to build their webs. The silk is produced in silk glands with the help of the spider's spinnerets. Spinnerets are special organs that allow the spider to decide what type of thread it needs for the web. The silk threads can be thick or thin, dry or sticky, beaded or smooth. The threads a spider uses to construct its web begin as a liquid, but they dry quickly in the air. When a spider begins a web, it releases a silk thread. It anchors the thread to some object such as a branch, or a corner of a room. As the spider moves back and forth, it adds more threads, strengthening the web and creating a pattern. Lines that go from the center of the web outward are called radial lines. They support the web. Threads that go around and around the web are called orb lines. The main reason spiders spin webs is to catch their dinner. When an insect, such as a fly, flies into a spider's web, it gets stuck on the sticky threads.
