Do you have any cats?
Of course I have a house cat and i call it house cat because i keep it as an indoor pet
Do you ever allow it outside
Of course no. I love its companionship  and its ability to hunt vermin.
What kind of vermin
Whichever type that are pests or nuisance animals that want to spread diseases or destroy my food 
They are good protectors then it sounds like
Yes, a protector is a good word for them as they have a strong flexible body, quick reflexes, sharp retractable claws, and teeth adapted to killing small prey.
They do seem to be very agile.
Yes, and they fit a crepuscular and predatory ecological niche.