From Jay: If one is extremely careful while using a map editor, it is possible to do so with animals, guests, and staff in a zoo. But since it is easy to do something that confuses ZT, I recommend to pause ZT, delete the zoo entrance, save the zoo, reload that saved zoo, and pause ZT again right away, so that zoo activity does not occur. Then make changes while ZT is paused, add the zoo entrance, possibly click on the zoo entrance to change the zoo name, save the zoo, exit ZT, remove the map editor, then go back into ZT to do any additional editing. Of course, I always recommend the Developer Map Editor instead of the ZA Map Editor, although the Developer Map Editor takes a little more effort to set up initially. However, for the mentioned problem, there might be an alternative to using any map editor. It might be possible to raise the terrain for the entire exhibit so that it is no longer hidden by the hills outside the zoo. Then when done editing the exhibit, the terrain for the entire exhibit can be lowered again. But of course if the hills outside the zoo are not desired in the finished zoo, then a map editor would have to be used.