Mice place objects in the wild to prevent them getting lost, researchers at Oxford University have discovered.

They found wood mice often leave piles of seeds, leaves, shells and twigs as 'rodent roadsigns' to find interesting locations and to retrace their steps.

The scientists claim the behaviour could be the first such sophisticated behaviour uncovered in mammals other than humans.

Oxford scientists Dr Pavel Stopka and Dr David MacDonald brought wood mice into a laboratory and filmed their behaviour.

The mice were given white plastic discs in an enclosure. It was soon noticed they picked them up and moved them as they began exploring further away from their nesting box.

The mice then stayed near the discs, but once the area became familiar the discs were moved and used again in other unexplored areas.

The scientists believe in the wild mice use the objects as landmarks in confusing environments such as vast fields of crops. The method is thought safer than scent-marking, which a predator could pick up.

Dr Stopka wrote in the journal BMC Ecology: "As far as we are aware, this is the first description of the use of portable waymarks by a non-human mammal."