There is a file that I used in my zoos at all times, UNLESS working on a contest zoo. It's from ZA, but I just discovered it is not in ZA hacks and utilities category, so we will have to get that changed right away. It is called ' Fil'emup' and it really helps the guests to settle down. When they eat, or rest, or use the restroom, it automatically fills all their needs values to 100%. If you are building a zoo strictly for your own enjoyment, this hack really makes it more fun.
I will attach this here until we can get it uploaded with author info into the ZA catalog.
Fill'emup.ztd