Destruction and fragmentation of their ancient woodland habitat have seen dormice disappear from half of their breeding range over the last 100 years.
Dormice hibernate from the end of October until early May. They wake up after dark and forage for flowers, fruit, nuts and insects.
Research has revealed that dormice can, contrary to previous belief, live amongst conifer trees, though the ideal habitat would be oak woodland with a mixture of hazel, bramble and honeysuckle to provide plenty of food.
North West Wales is really on the northern and western fringe of the dormouse's natural range and may not ever have been very good for dormice. They do not like the wet, damp weather.
The Countryside Council for Wales, Chester Zoo and partners are studying dormice at Bontuchel near Ruthin. They've put up 250 nest boxes, and in 2005 they found 150 dormice, making it one of the biggest populations in north Wales.
There are four key areas for dormice in Wales: central and eastern Monmouthshire, east Montgomeryshire, south east Radnor/east Brecon and Carmarthen/west Glamorgan.
Dormice, whose name is thought to come from the French word, dormir, meaning 'to sleep', spend three quarters of their lives snoozing.
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