They use a targeted selection process. Asking behavioral questions in the format of "Tell me about a time when..." Make sure your responses describe the situation, your actions, and the outcome.

Went through a presentation at first, describing the job position. Then answered basic questions, like tell me about yourself and how you feel working with animals. Good to know that you work a lot of weekends and some holidays, like New Years, Christmas, Thanksgiving, etc... Also good chance you need to have some late nights.