As for those spiders that are not in the habit of building webs, but which roam freely on the ground, on trees, on plants and on walls, they always reel out a "dragline" behind them, which they secure every so often to the surface they are on. When they jump from a high place or are blown by the wind, this dragline provides the best of safety lines.
至於平日不結網的蜘蛛，自由往來於地面、樹叢、牆壁間，隨身拖著一根「曳絲」，遊走一段距離後就打樁似的固定一下絲線，由高處跳躍或遭風吹墜落時，用來垂掛身體，是最佳的安全索。