英语听力：自然百科 虫虫兄弟—7（在线收听）

 But such tiny creatures, these sloppy feeders can carry many diseases. One of the worst on record is the Black Death, the great plague that swept across Europe，wiping out one third of the population. Breakfast shift over, the family heads off, everyone except Maria who is having a real day of work. She is not exactly home alone, even a clean kitchen can harbor six and eight-legged intruders. And it comes to microscopic feeders, there are other hot spots. Up in the bedroom an army of thousands is on maneuvers. Shaking the sheets sends dust mites cascading through the house. But many more stay in the barracks. The creatures which live on dead flesh, bed linen, pillows, and matresses are a 24-hour all-you-can-eat diner. Dandruff is a particular favorite. The average bed is taught to contain up to 10 million mites. That might sound grim, but it's not as gruesome as the waste they leave behind. Dust mites are the scourge of asthma sufferers. As their excrement decomposes, it turns into a fine dust which irritates the lining of the lungs and nose. As the house is bombed with dust mite droppings, there's a holy war going on in the wardrobe. The clothes are being butchered, and this hairy youth is the culprit, the larva of a carpet beetle. The carpet beetle is one of the few creatures with the guts for this type of work. Its body contains enzymes which can break down carotin, the main protein in head.