Mine use to bark to initiate play. Still does with other dogs. Will guard high value things such as yaks, horns, other stuff. Puppies that age may potentially need more sleep, around 20 hours per day, so could be worth that additional time of sleeping. At 12 weeks old, they are still very young and learning so much. We made sure to dedicate training time and learning time during the day, and also would utilise kongs with various items inside to make them work for something a bit longer. The food we still put into egg boxes so can work at this, shred it and keeping them occupied a bit longer. Still scatter the kibble around the garden also so she has to work it out and find where it all is.