Old World Mice and Rats

The Muridae family is the largest and most successful group of rodents, with over 700 species worldwide, including mice, rats, voles, and gerbils. They usually have pointed noses, large rounded ears, and long scaly tails, although the size and shape of these features vary a lot between species. Their teeth include one pair of ever-growing front teeth in each jaw. Their size ranges from very small harvest mice to much larger brown rats. They originally come from Eurasia, Africa, and Australia, but murids have spread to almost every land habitat, from deserts to tropical forests. Some species have spread across the world thanks to human activity. In the UK, native species include wood mice, yellow-necked mice, and harvest mice, along with introduced brown and black rats. Most murids are active at night, eat a variety of foods, and are very adaptable. They have a strong sense of smell and hearing. Their ability to breed quickly and take advantage of different environments makes them some of the most common mammals in the world.