Many cats can be frightened of company, visiting pets, loud children, dogs or other cats in the home. It is important that cats have a place where they can feel "safe". That place may be a pet taxi hidden under the bed, a comfortable cardboard box in the corner of the room or hidden retreat in the closet.
It is also important that cats that live with dogs always have the opportunity to have a place separate retreat away from the dogs. This may be as simple as a box on top of the dresser or a separate room that the dogs can't access. Some cats appreciate a kitty door on one room in the house that only they can access to allow for quiet private time.