Fast Ager Trap
From Creatures Wikia
"This agent runs in the background searching for creatures which seem to age too fast. Any suspected fast-ager creature will be exported automatically, and an "F_" is appended to the beginning of the file name of the creature. The agent will also create a logfile which can be found in "my worlds\nameofworld\journal\fastager.txt". The moniker, name of the creature, and age in which the creature reached adulthood (in game ticks) will be logged to the text file. Fast Agers which are cloned as adults, and therefore have no creature history will not be detected by this agent."