Constructed from a mix of concrete and FSC certified wood fibres, WoodStone® nest boxes safeguard against attacks from predators including woodpeckers, cats and squirrels. Unlike a traditional wooden nest box, these boxes will not rot away or deteriorate. Every WoodStone® nest box from CJ Wildlife is guaranteed for 10 years. The material insulates the nest which creates a more consistent internal temperature than an ordinary wooden box. This is especially important during the breeding season and ensures that young birds have a greater chance of survival. We recommend using aluminium nails to hang due to the weight of the nest box and to limit any damage caused to trees. This nest box has been designed in conjunction with birding experts across Europe where during research studies, the black fronts are often used for numbering boxes with chalk, however it also makes an attractive colour combination that you may prefer in your garden. 28mm hole nest boxes will be used by Tree Sparrows...