They are beginning to play-fight. You can see in this picture how they take stances against one another, prancing around on their tippy-paws sideways, with fur bushed out and tail straight up. Then...pounce! They land on another kitten, only to fall over backwards, tiny feet flailing to gain balance and get upright once again. Then they try again. They are practicing their hunting skills on each other, but with their fluffy bodies and relatively soft claws, they do no damage to each other. Yet it teaches them coordination, balance and agility that they are going to need to match their skills against the "big" cats in the house.

