From Creatures Wikia
Creatures 3 and docked Docking Station worlds contain two airlocks, one in the Bridge and one in Engineering. An airlock can be opened and closed by pressing the button located outside it and activated by pressing the button inside (activating an airlock will also close the door temporarily). The airlocks have a number of uses including the killing of Grendels (or any other creatures), the removal of certain critters and the destruction of agents that are either too big for the recycler or not effectively removed by it.
Did You Know?
Holding agents (and critters) inside the airlock when it is activated will cause a glitch with the physics of that particular object, which in most cases causes the object to become extremely bouncy.
Although entertaining, it may be difficult to catch a glitched object while it is bouncing at speed, and certain agents can also cause problems in the game if they are set bouncing in cetain areas. For example, making a Stopper Plant from Norngarden bouncy and setting it off on the upper levels of the Bridge or Engineering can send Gaia on a little trip along the corridor (if she is installed).
Blueprints and some third party agents are not destroyed when blasted out of the airlocks and will become afflicted by the same glitch.