I know how to take it away:
-Go to where your Zoo Tycoon 2 is installed.
-There, open with WinRar the file x110_000.z2f, and there go to entities\units\animals\ai, and find the file Ratel.xml.
-Take it from there. That'll make a copy of that.
-In the file takne away, open it with notepad and find this:
Delete it, and ONLY it.
.Pick a .z2f, like one from a Download, and start emptrying it, but before that, put the modified Ratel.xml file in entities\units\animals\ai of the .z2f file you are working with. Then, delete out of it all other content (from the one of an User-made DL, not the _x110_000 file).
-Rename the .z2f something starting with z, so it'll be taken into accout.
-Play the game. It should work.
(You need to press "Quote" to see the code to be deleted, for some odd reason.)