By Matthew Power

A recent Johns Hopkins University study published in the Journal of Allergy and Clinical Immunology turns the heat up on household mice. They describe the little critters as tiny terrors that can cause fires by chewing through electrical wires or trigger asthma attacks with the dander and urine they leave behind.

Dr. Robert Wood, the study's lead investigator puts the mouse second only to the cockroach in terms of its contribution to allergens in the home.

What can builders do to keep mice at bay? The National Pest Management Association (NPMA) urges keeping areas around buildings clean and closing all cracks or gaps around wiring or pipes to less than 3/8 inches. Mice can squeeze through some very small holes.