Trenkle German Black Forest weather house Heidi TU 835 Colour: Coloured Height: 14 cm/5.6 inch The weather house is made of wood. This is how a weather house works: There is a gut string inside, which reacts to all changes in the air humidity. Depending on whether the air is dry or humid, the gut string changes its position and twists more or less, so that the female turns outside when it is dry and the male, when it is humid.