Puppy's body language
This is when you want to start to watch the puppies' body language; it is the best time to gauge how they will behave later on in life. You can shoot air guns and watch the tails of the puppies; they can transmit a lot of what the dog is feeling. Is it wagging, stiff, tucked, upright, curly over the back? These are all important indicators of future temperament. A wagging tail shows that a puppy is curious and willing to take a chance and listen to human directions. A stiff tail held over their back show that the puppy is a dominant puppy who will work well under certain types of environments such as for patrol work.
Around this time you will also want to put new footing into the puppies' play area, such as cardboard boxes, plastic milk crates, wooden planks, carpeting, linoleum. The different footings help the puppy learn how to adjust its balance, to maneuver its feet and shift its weight. You can also do puppy agility with the balance beam and low jumps to see how the puppy maneuvers through these obstacles. A puppy that is willing to explore, have good recovery time, and maintain eye contact is a good candidate for future SAR work.
To later succeed in such work, a puppy must show they have the endurance needed to work without quitting and the intensity to search until they find the object of their desire. One simple game you can play is to throw several tennis balls into the puppy's pen and watch what it does, does it pick it up, chase it, or hide it. You can then move on to other item such as wooden dowels, then PVC piping, then metal spoons--you need a puppy that is curious and willing to pick up different objects. You want a puppy that is willing to play and does not give up; you have to take the object away for them to stop playing. A puppy that is possessive of their object is also an asset for SAR training. A innate desire to retrieve and find is what you are looking for at this stage. You might think this is young but a properly bred puppy will shows these drives, they might only surface at the times you are testing but that is enough. By the seventh week you can start their training. A puppy should show signs it is intelligent and able to think through problems. A dog with lots of play drive but who cannot think is of no use; it will burn out quickly and not have the stamina to continue. You also want a puppy that does not fold under correction but rather learns and continues to work without holding a feeling of resentment.
Two to three months: The puppy's brain is now developed enough for it to begin receiving training in earnest. It is also the time to perform some specific testing and evaluation. As we mentioned earlier this is also still a key time in the socialization and imprinting process of the puppy.