Mice are small mammals that are found on every continent except Antarctica. They have long tails, large ears, and pointed snouts. They range in size from a few centimeters to over 10 inches long and can weigh up to 45g. Mice feed mainly on seeds, fruits, nuts, insects, and sometimes other small animals. Most species of mice live in burrows or tunnels they dig underground; some live in trees or dense vegetation above ground. Although they are considered pests by many people because they often invade homes, mice can also be beneficial to humans through their role as natural predators of harmful insects like beetles and caterpillars. Mice are also important laboratory animals used for research into diseases such as cancer and heart disease.