Mice do not especially crave cheese, but they do make faces
The cartoon mouse chasing cheese is mostly myth: mice prefer sweet, high-calorie carbohydrates and eat cheese only when nothing better is around. Meanwhile, scientists at the Max Planck Institute used machine vision to show mice pull recognisable expressions of pleasure, disgust, pain and fear.
A mouse is a small rodent with a pointed snout, round ears, a long scaly tail and a very high breeding rate. The most familiar species is the house mouse, Mus musculus. Mouse and rat are not scientific categories: when a new muroid rodent is found, it tends to be called a mouse if small and a rat if large. The deer mouse, for example, belongs to a different genus entirely, and voles are sometimes loosely called field mice.
Mice are among the most successful mammals on Earth, adapting to almost any environment. Cats, foxes, birds of prey, snakes, some lizards and even certain arthropods eat them, yet populations stay abundant. Mostly nocturnal, they have weak eyesight but sharp hearing and rely on smell to find food and avoid danger. Wild mice dig elaborate burrows with long entrances and escape tunnels, and in at least one species the burrow design is inherited.
In the wild they eat mostly fruit and grain, while city mice will take almost any scrap. They can also be serious pests, damaging crops and buildings, carrying parasites and spreading disease through droppings. In North America, inhaling dust contaminated with mouse excrement has been linked to hantavirus.
Their biggest role for humans is in the lab. Mice are the most widely used mammalian model organism, more common than rats, because nearly all of their genes have human counterparts. Their genome, about 2.7 billion base pairs on 20 chromosome pairs, has been fully sequenced. The white lab mouse is valued for its uniform traits, and knockout mice, with one or more genes switched off, are used to model conditions such as Down syndrome and several cancers, though animal rights activists often object to such work.
Source: Mouse
