Help - animal boxed outside its habitat

[mikek21]

Apparently I did not notice that one of my hippos escaped and now the poor thing has been boxed outside of it's habitat for a long time (that is the actual message). How do I move him back into his habitat. I can click on the crate but it does not let me unbox the animal. I have tried placing vets right near the crate, but they just walk away. What do I

 

[DoesntMindMuck]

I have the same problem but I don't know if he escaped. i was able to get the Hippos crate into the habitat by messing with the terrain but i still cant unbox him