a lizard just lost its tail. Tail is moving, lizard too. What is making lizard's tail moving if there is only one soul?
That one is from my sons...he he
When you have a fan and you pull out the plug even though the electricity is disconnected the fan still moves for a bit. I remember reading Prabhupada gave this analogy for karma once.
Just as a non-living machine moves on batteries and stops moving when the batteries are empty, the nerves of the lizard's tail are moving in a similar way. As soon as the chemical reaction (electrical current) is neutralized by time (batteries running empty), the tail stops moving. It's not that the tail takes on a new life, independently from the lizard.
In the case of a worm, when cut in two, the two parts continue to live independently. In one part of the worm's body the original soul remains the 'owner' of the body. In the other part of the body, an opportunity is created for another soul to enter that body. A soul is placed in that part and it takes on a new life. (Ghosts are pleading to Siva; "please give me a body to live in". These cases are such opportunities for ghosts to get a suitable body to continue their way in the cycle of birth and death.)