The Host may ask two questions, including WHAT the Service Animal is trained to do.
If the Animal is left in the room all day, then it is not a service animal and the guest lied. That would be grounds for removal, correct?
In a certain case, The Host wanted to keep the money (monthly), so she let them get away with leaving the dog in the room. The Host complained, but let them stay anyway. So this empowered the dishonest guest to continue doing what they do. This also sets a bad example and the guest with the unruly German shepherd are still out there today telling everyone else how to get away with it.