Mice and rats are nuisance animals that can cause damage to buildings, humans, animals, and the environment. They release a foul odour and can be distinguished by their size - mice are smaller than rats. Rats tend to take the same route to food sources every day, but mice are more adventurous and explore new paths to look for food. The main rodents to worry about are the house mouse, roof rat, and brown rat. It's important to get rid of these rodents quickly because they can spread diseases and cause other problems.