If non-zero, there is a chance of 1 divided by the given value each turn for any
thing of the selected type to emit an offspring to a random neighbor cell if one
is available that is passable and not inhabited by a thing of the same same type
If non-zero, there is a chance of 1 divided by the given value each turn for any
thing of the selected type to emit an offspring to a random neighbor cell if one
is available that is passable and not inhabited by a thing of the same same type