Reviled as the most destructive mammal pest, Norway rats compromise the well-being of humans and cause costly damage to manmade structures. They can live as long as two years in the wild and produce as many as 20 young in that span of time. Norway rats are mostly active at night, have poor eyesight, and rely on their other senses to guide them. Actually quite intelligent, Norway rats quickly detect and avoid unfamiliar objects that show up in their chosen environment, such as traps and baits. Their rapid rate of reproduction and elusive nature make them particularly challenging to control.