身有灰色细鳞，腹部末端有尾须三根，。圆形直径约 l ～ 2 毫米，行动迅捷径，稍一有声音，像鱼一样逃走。喜欢温暖、潮湿的地方，夜间活动昆虫，遇光便逃跑，通常浆糊、胶质为其食物。对书籍、衣服、字画、纸箱等为害，也常以人们不太翻动的旧书和贮藏品取食为窝。也为害羊毛衫、毛呢等服装。
毛衣鱼雄虫体长 9 ～ 13 毫米，黄铜色，背面有微黑鳞片，尾须三根外，另有复刺二对。雌虫个体大于雄虫，产卵管很长，产卵管有 3 毫米左右长。毛衣鱼成虫性活泼，雌虫将卵散产或成块地产在贮藏食品附近，初龄幼虫身上无鳞片。一年发生数代，喜欢生活在黑暗、潮湿或密闭的场所。
为害物有丝绸、毛料、衣服、布匹、纸张、花生、芝麻，甚至中药材等。为害羊毛衫及呢绒服装时，蛀孔光洁，不见虫粪，形状圆形或不定形。圆形直径约 l ～ 2 毫米。
每年衣物翻晒收藏时，要避开害虫交配、产卵季节。藏衣人箱时，手感柔软的、 贵重的丝毛衣服与手感粗硬的衣服要分箱存放，衣箱内放入防蛀药品(如樟脑丸) 。
DESCRIPTION: Silverfish are small, soft insects without wings. The abdomen has three filaments extending from it.Silverfish are not often seen by homeowners because they are nocturnal and can run very swiftly. Occasionally, they are found in bathtubs. They crawl in seeking food or moisture and can't climb out. These insects prefer vegetable matter with a high carbohydrate and protein content. However, indoors they will feed on almost anything. A partial list includes dried beef, flour, starch, paper, gum, glue, cotton, linen, rayon, silk, sugar, molds and breakfast cereals.
HABITAT: Silverfish normally live outdoors under rocks, bark and leaf mold, in the nests of birds and mammals, and in ant and termite nests. However, many are found in houses and are considered a pest, or at least a nuisance, by homeowners. Usually they are found trapped in a bathtub, sink, or washbasin.
LIFE CYCLE: Adults lay eggs in small groups containing a few to 50 eggs. The eggs are very small and deposited in cracks and crevices. A female normally lays less than 100 eggs during her lifespan of two to eight years. Under ideal conditions, the eggs hatch in two weeks, but may take up to two months to hatch.
The young nymphs are very much like the adults except for size. Several years are required before they are sexually mature, and they must mate after each molt if viable eggs are to be produced. Populations do not build up rapidly because of their slow development rate and the small number of eggs laid.
TYPE OF DAMAGE: A household pest, they feed on cereals and non-food items such as paste, paper, starch in clothes, rayon fabrics and dried meats.