Have you heard or read somewhere that martens can fit through a hole diameter of only 2cm? Are you worried that martens can easily get into your attic through every crack? Find out here how wide a hole has to be for a marten to fit through.
What hole diameter is passable for martens?
An adult marten will fit through holes at least 5cm in diameter, while younger martens may be able to fit through 3cm openings. For smaller holes, martens can use their sharp teeth to expand them to the required size.
Anatomy of martens
Beech martens are mammals and as such have a solid skeleton. They have a head and torso length of 40 to 60cm and a total length (including tail) of up to 90cm. The head is relatively small, the body is narrow and stretched. The shoulders are also relatively narrow. The skull is the widest part of the skeleton and therefore determines where the marten can fit through.
Size differences in stone martens
The width of the skull varies depending on the age and sex of the marten. Females are slightly smaller than males and marten cubs are only 15cm tall when they are born. The good news: The boys are only independent from the age of 5 months and by then they have already reached a decent size.
Skull size of martens
Marten skulls are about 10cm long and 4 to 5cm high and wide. Logical conclusion: An adult marten can only fit through holes that have a hole diameter of at least 5cm. A young marten that has just come out of the nest may fit through holes about 3cm in size.
Which hole can a marten fit through?
The bad news is: Martens have very sharp teeth and where there is a will, there is a way. If the hole is too small for the marten, but the material can be chewed - e.g. made of wood or soft rock, a marten can easily expand a 2cm hole to the necessary size. Under certain circumstances, martens can also get through holes that are smaller than 5cm.
Wire mesh and martens
A wire mesh (€17.00 on Amazon) with a hole width of 2cm should keep them from getting inside the house, because wire is also a challenge for the marten's teeth. It is important to attach the wire securely, because martens are very clever and may bend it to suit their needs.
