According to his company's website, Mr Dini's industrial sized 3D printer uses sand and a special binding agent to create a "marble like material" stronger than cement.

BBC: Landscape House

Even though the Demjanjuk conviction isn't considered legally binding because he died before his appeals were exhausted, the special German prosecutors' office that deals with Nazi crimes has said about 50 other people in the same category are being investigated.

WSJ: Germany Arrests Man Who Worked at Auschwitz

For these bees you can buy special homes from garden centres, or simply make your own by collecting and binding together hollowed out small branches.

BBC: Leicester - DIY: Getting creative with nature