New Delhi, Nov. 22 -- Cockroaches are often seen as annoying pests that hide in the kitchen at night, but new research shows they may be doing something much worse. Scientists from North Carolina State University found that cockroach infestations release high levels of allergens and bacterial endotoxins into the air, making homes less healthy for the people living in them.

Endotoxins are tiny fragments of bacteria that are released when bacteria die. Because cockroaches eat almost anything, food crumbs, grease, paper and even waste, they carry a wide range of bacteria in their gut. When they leave droppings, these bacteria break down and release endotoxins into household dust. The researchers found that a big chunk of endotoxins in indoo...