Adults vary from brown to grey in colour with a 7-9 cm body length. Their tail length is 8-10cm long (which is 80% of its body length). Its large ears are considerably smaller than those of its close relative the Field Mouse and the house Mouse also has small eyes.
Sexually mature at 8-12 weeks females can produce a litter every three weeks with 5-6 young per litter. The young are born without fur and are blind. Weaning takes 3 weeks – during which time the female can become pregnant with the next litter. The Life span for adults is about nine to twelve months.
Mice cause damage to structures and property, and they may transmit diseases such as salmonellosis (food poisoning). They have a characteristic musky odour that identifies their presence – they are occasionally seen during daylight hours. Other signs of infestation are droppings, fresh gnawing, tracks and smear marks.
Nests are often found in sheltered locations and are made from fine shredded paper or other fibrous material. They prefer cereal grains, but will eat many kinds of food. They are sporadic feeders, nibbling bits of food here and there. They have keen senses of taste, hearing, smell, and touch and are excellent climbers and acrobats. They will run horizontally along wire cables or ropes and can jump up 33 cms from the floor onto a flat surface and can squeeze through openings greater than 5mm in diameter.