From Creatures Wikia
The bootstrap is a folder in Creatures 3 and Docking Station that includes CAOS scripts to be executed upon startup. This includes nearly all scripts for CAOS-based game elements, including the world map, the agents that populate a default world (such as toys and ecology), and the game interface. By replacing or modifying these scripts, one can affect the setup of new game worlds. For example, MNBs' 'Please buy...' disabler works by replacing that script on startup of a new world. Bootstrap scripts are executed only once when a new world is created.