Rodents have a pesky past, spreading disease and eating seeds collected for human food supply. Fleas residing on black rats carried by merchant ships brought the Black Death or bubonic plague to Europe killing 30-60% of the population, millions of people between the 14th and 19th Century. Infected rodents carry hantavirus, a cardio-pulmonary syndrome, although rare can be fatal to humans, is transmitted through urine, droppings or saliva, which can be contracted by breathing in the airborne virus. Beavers cutting down trees and flooding property sometimes frustrate homeowners. Squirrels can get into attics and mice into walls disturbing residents with scratching and feces, not to mention chewing open bags and clothing.