One time I heard Eevee cry, so I looked around for her. It sounded like it was coming from the back door where the doggie door is. So I look outside for her, don't find her. I look everywhere inside, run around frantically outside, everything, still can't find her and she never made another sound. I became convinced the cry I heard was her death cry as she was taken away by a coyote or owl or something just outside the back door. I was freaking out--then we found her in the closet by the back door.

Why didn't she just cry again to let me know where she was?
When my aunt's Yorkie was a puppy, she left her with her mother to be dogsat. The puppy disappears outside. So the whole family rushes home and looks for her. Turns out she had fallen down between the rails of a cattle guard and was trapped in a hole in the ground. She was barking, but the bark was so high-pitched the grandmother hadn't been able to hear her!
They can get trapped in the weirdest places.