Phoenix, our four year old orange long-haired tabby, has been acting strange since yesterday evening. She has been hiding underneath our bed, and then she moved to behind our couch. She isn't breathing hard, vomiting, or anything like that. She seems relaxed, just tired. However, this is unusual for her. She usually is up and around, being a "brat", as my wife likes to affectionately call her. It hasn't been quite 24 hours since she has started this, and we had thunderstorms in the area last night - she usually hides when the thunder and lightening starts. However, she usually comes out right after the thunderstorm has stopped. This time, she hasn't. We plan on taking her to the vet if she continues this behavior, but has anyone else has experience with this type of thing? Thank you.