Most of the mice held at the Max Planck Institutes come from the Institutes’ own breeding programmes ... The mice are kept in see-through plastic cages with an area of at least 370 square centimetres.

It is best to begin breeding mice before they are 3 months old ... it is best to leave the male alone in the cage for a few days before introducing the female. If either partner is overly ...

whereas the mice formerly lived without cage companionship 17. The housing of stud males for breeding purposes is still likely to require individual cages. Thus it is particularly important to ...