The Hazel dormouse is a European Protected Species (EPS). It is against the law to damage or destroy a dormouse breeding site or resting place (summer or hibernation nest), or deliberately to capture, kill, injure or disturb a dormouse

The Hazel dormouse, Muscardinus avellanarius, is one of our most endearing yet elusive mammals. It is nocturnal, extremely agile and spends most of its waking hours in trees and bushes. Dormice are only generally active between April and October.

They are found in every Welsh county except Anglesey, and yet they live in low-density populations throughout their range. Their numbers have fallen by around 20% between 1991 and 2000. This page cannot cover all aspects of the law, but is an introduction to show how you can help to protect dormice.


The Hazel dormouse is protected under the Conservation of Habitats and Species Regulations 2017, known as the ‘Habitats Regulations’.

Under the Habitats Regulations, it is an offence if you:

  • deliberately capture, injure or kill any wild animal of an EPS,
  • deliberately disturb wild animals of any such species,
  • damage or destroy a breeding site or resting place of such an animal

Disturbance includes, but is not limited to, any disturbance which is likely:

1. to impair their ability –

  • to survive, to breed or reproduce, or to rear or nurture their young, or
  • in the case of animals of a hibernating or migratory species, to hibernate or migrate; or

2. to affect significantly the local distribution or abundance of the species to which they belong.

Defra and the Welsh Government will publish a joint guidance document on the interpretation of the offences relating to disturbance, and damage and destruction of breeding sites and resting places.

There are other offences relating to possession, transport and sale.It is, however, legal for you to tend a disabled dormouse with the intention of releasing it, or to kill a dormouse that cannot recover, as long as the injury was not a result of your unlawful act (Habitat Regulations 44(2); W&CA 10(3)(a)(b)).

Under the Wildlife and Countryside Act 1981(as amended) it is illegal to:

  • intentionally or recklessly disturb any dormouse while it is occupying a structure or place which it uses for shelter or protection, 9(4)(b)
  • intentionally or recklessly obstructs access to any structure or place used by a dormouse for shelter or protection, 9(4)(c)
  • sell, offer or expose for sale any dormouse, 9(5)

Natural Resources Wales (NRW) issues licences under Regulation 55 of the Habitats Regulations to allow you to work within the law. You might need a licence to undertake woodland management, scrub clearance or a development, for example. See ‘Dormouse Licensing’ and ‘Do I need a European Protected Species Licence?’ for more information.