All mice are brown in colour, with curly tails and round ears. Their noses and the insides of their ears are pale pink. Typically, they are enclosed within areas when they are first seen, walking on their hind legs.
Having no special attack, mice pace around the areas of the game in a set pattern. This makes it easier for the player to kill them with a bomb, since their movement can easily be plotted. Sometimes, destroying certain blocks within the area will change a mouse's movement pattern.