Martins Mice (Puffin Books) by Smith Dick King - old paperback
Unlike most kittens, Martin doesnt like eating mice - let alone catching them. When he catches one by mistake he decides to keep it as a pet and soon Drusilla the mouse is established in an old bath tub in the attic. Martin is kept busy getting food, water, bedding - and then Drusillas babies start to arrive. How can Martin cope with all his mice?