House mouse

This tiny traveller followed people around the world. About 15,000 years ago mice moved into settled homes for shelter and leftover food. Later, farms with stored grain helped them spread with people to towns and farms on every continent except Antarctica. In Australia they are newcomers, now found right across the country, seldom far from houses, sheds and barns. They also live in nearby fields and woods, and often slip indoors when autumn turns cool.

It is a rodent, a distant cousin of the giant capybara shown beside it. Both gnaw with four strong front teeth. The mouse itself is plain brownish-grey with a pointed snout, large thin ears and a long thin tail about as long as its body. An adult's body, not counting its tail, is about as long as your thumb, or a little longer.

Inside, it is surprisingly like you. It shares most of its genes with people, so scientists study mice to understand human illness and find new treatments.