If you find small wads of soft materials or paper, you may have found rodent nests. You might even smell rodent urine or be able to hear them scurrying around.
[header] How to prevent hantavirus pulmonary syndrome (hps ) [title] Recognize signs of an infestation. [step] Look for small pellets of rodent droppings about ¼-½ " (0.5-1.0 cm) in size. You may also see signs of gnawing on your furniture or rodent tracks in dusty spaces.